Naomi Osaka defeated Elise Mertens in Bad Homburg and reached her first quarterfinal of the season
Naomi Osaka continued a successful week on grass in Germany's Bad Homburg with a 6:3, 6:3 victory over Elise Mertens in the second round of the WTA tournament Bad Homburg Open powered by Solarwatt 2026. According to the WTA report, the Japanese tennis player reached the victory in 67 minutes, without losing a set, with a very effective attacking performance that brought her a first place in the quarterfinals in the 2026 season.
Naomi Osaka advanced to the quarterfinals of the WTA Bad Homburg Open 2026 after she defeated Belgian Elise Mertens 6:3, 6:3 in the second round on Tuesday, June 23, 2026. The duel in Bad Homburg, a city in the German federal state of Hesse, was played on a grass surface as part of the tournament that the WTA lists as one of the last major competitions before Wimbledon. According to the official WTA report, Osaka finished the match in 67 minutes, with seven aces, 22 winners and only eight unforced errors. Such a ratio is especially important on grass, where serves, first shots after the serve and short rallies often turn into the decisive difference between a controlled victory and an uncertain match. For Osaka, this result also meant her first quarterfinal appearance in 2026, which gives the victory additional weight in the context of her return toward consistency at the top of the WTA Tour.
A fast start and better control of key moments
According to the WTA analysis of the match, Osaka entered the first set extremely aggressively and quickly took a 5:0 lead. Mertens then managed to reduce the deficit to 5:3, briefly opening the possibility of a comeback, but the Japanese tennis player did not allow a repeat of the scenario from the previous round, when against Magdalena Frech she had also held a large lead before a shorter lapse. This time Osaka, as the WTA described, maintained a calmer rhythm in the closing stage of the set and closed it without further complications. Such a reaction was important because Mertens is a player who rarely gives away points in a row, reads an opponent's rhythm well and often uses every phase of uncertainty to return to a match. Osaka, however, managed to maintain the offensive plan: press with the serve, dictate with the forehand and shorten the exchanges before the Belgian established her recognizable defensive balance.
In the second set, the key difference remained the same: Osaka used the first shots better and more often took the initiative as soon as a shorter space for attack opened. The WTA states that her forehand produced 11 winners, which clearly shows where the main tactical axis of the match was. Mertens tried to lengthen the rallies, change the height of the ball and draw her opponent into more patient exchanges, but Osaka played a large part of the match with enough discipline to avoid unnecessary risk. The finish further confirmed the difference in confidence: according to the official WTA report, Osaka won the last eight points of the match, and the penultimate one she finished with another forehand. Such a run at the end of the match shows that the victory was not only the result of a strong start, but also of the ability to maintain intensity until the final game.
Without losing a set on the way to the quarterfinals
Osaka reached the quarterfinals in Bad Homburg without losing a set. In the first round she defeated Polish player Magdalena Frech 6:4, 6:1, and according to reports from the tournament that match had been interrupted by rain at 5:4 in the first set before the Japanese player completed it convincingly. The victory over Mertens was even cleaner in terms of tempo and impression, because Osaka against the experienced Belgian tennis player managed to connect the serve, return and baseline attack into a compact whole. The WTA particularly emphasized that this was her first quarterfinal on grass since the tournament in 's-Hertogenbosch in 2024, which further confirms that Bad Homburg was not only about moving through the draw, but also about a result with broader sporting significance. On a surface on which every small technical instability is more visible than on hard or clay courts, Osaka showed against Mertens that her first strike can still be among the most dangerous on the Tour.
Mertens entered the tournament after a 6:3, 6:3 victory over Alexandra Eala, so the duel with Osaka was expected to be a serious test for both players. The Belgian is known for stability, quality movement and the ability to adapt, and her experience in singles and doubles competition often enables her to find solutions even when the opponent is more aggressive. According to the WTA profile, Mertens has won several WTA titles in singles during her career, and in doubles she has built one of the most successful careers of her generation, including Grand Slam trophies. Still, in this match she did not manage often enough to pressure Osaka's second serve or neutralize the first attacking shots from the other side of the net. The 6:3, 6:3 result therefore reflects not only the difference in the number of winners, but also the fact that Osaka had a clearer plan and better execution in the key sequences.
The head-to-head record moved further in Osaka's favor
With the victory in Bad Homburg, Osaka, according to the WTA, increased her lead in head-to-head meetings with Mertens to 5:3. Even more important for the grass part of the season is that she is now 2:0 against the Belgian on grass, after also defeating her on the way to the quarterfinals in 's-Hertogenbosch in 2024. That data does not mean that the balance of power between the two experienced players is one-sided, because their previous duels showed different tactical patterns and momentum shifts. Still, on the fastest surface Osaka has a clear advantage if she manages to regularly land the first serve and move into the court early after shorter balls. In such a setup, Mertens must find a way to extend the point without retreating too deeply behind the baseline, and on Tuesday she did not manage to do that often enough.
For Osaka this victory is valuable also for psychological reasons. The WTA in its profile states that she is a former world No. 1 and a four-time Grand Slam champion, with titles at the Australian Open and US Open, and her career after returning from maternity leave went through phases of adaptation, searching for rhythm and gradually returning to the final stages of major tournaments. In 2025, according to the WTA profile, she returned to the Top 20 after finals in Auckland and Montreal and a US Open semifinal, while in 2026 Bad Homburg brought her the first quarterfinal result of the season. Such a context explains why a victory in the second round of a WTA 500 tournament cannot be viewed merely as a routine passage. It comes in a week in which every win on grass can change the impression before Wimbledon, but also confirm that the game is based on concrete elements, not only on reputation.
Bad Homburg as an important stop before Wimbledon
The Bad Homburg Open powered by Solarwatt 2026 is being held from June 20 to 27 at TC Bad Homburg, according to the official information of the tournament. The WTA states that it is a WTA 500-level tournament on grass, which has been in this category since 2024 and is played in the final week before Wimbledon. According to the WTA tournament guide, the main draw of the singles and doubles competitions began on June 21, the second round is scheduled for June 23 and 24, the quarterfinals for June 25, the semifinals for June 26, and the final for June 27. The official Wimbledon schedule confirms that the London Grand Slam 2026 is played from June 29 to July 12, which makes Bad Homburg especially important for players who want to test movement, service patterns and rhythm on grass immediately before the biggest grass tournament of the season. In such a calendar, even one match can have greater value than the result itself, especially for players seeking security in the short interval between preparatory tournaments and the Grand Slam.
The tournament in Bad Homburg has gained greater significance in recent years precisely because of the combination of surface, timing and WTA 500 status. According to the tournament's official website, the competition is held in Kurpark, and the organizers present it as part of grass-court preparation with conditions intended to resemble Wimbledon. The WTA points out that the 2026 draw included three Grand Slam champions and several players from the top of the rankings, which further increases the value of every victory in the earlier rounds. For Osaka this means that the quarterfinal did not come in a weaker or transitional tournament environment, but in a field in which every round could bring an opponent with serious experience at the highest level. Bad Homburg has therefore become a place where not only form is tested, but also the ability to adapt quickly to the specific demands of grass.
Serve and forehand as the foundation of victory
The most important technical signal from the match against Mertens was the way in which Osaka connected the serve and forehand. Seven aces speak of the direct impact of the serve, but even more important is that she opened a large number of points with enough quality to immediately take over the attack. According to the WTA, she had a total of 22 winners with only eight unforced errors, a ratio that on grass rarely leaves an opponent much room. When a player of Osaka's profile reduces the number of hasty errors, her power from the baseline becomes even more pronounced because opponents must defend both the depth and direction of the shot. Mertens tried in several phases to slow the rhythm, but Osaka changed direction often enough and kept the Belgian outside her comfort zone.
It is especially important that the Japanese tennis player in Bad Homburg showed a better balance between aggression and patience. In the earlier stages of her return to the Tour, this was often the question: whether she could maintain attacking intensity for long enough without a sudden drop in concentration. Against Mertens the answer was positive, at least within the framework of one very clear match on grass. Osaka did not have to play long defensive sequences or rely on waiting for Belgian errors, but directed most of the key points toward her own strongest weapons. Such a pattern is particularly relevant for Wimbledon, where the first shot, precise positioning and quick reaction after the serve are often decisive already in the early phase of a set.
Mertens remains dangerous, but without the right answer in Bad Homburg
Elise Mertens leaves Bad Homburg after a match in which she had moments of resistance, but did not find enough consistency to change the course of the encounter. According to the WTA profile, the Belgian player has a rich career in both competitions, including ten WTA singles titles and numerous doubles successes. Her ability to combine defensive stability, a good return and tactical patience usually enables her to complicate matches against stronger hitters. In this case, however, Osaka reached neutral or attacking positions too quickly, so Mertens could not use her greatest advantage often enough: redirecting the rhythm and lengthening the exchange until the opponent's error. When in the first set she reduced the score from 0:5 to 3:5, she opened space for pressure, but did not manage to turn it into a complete change of dynamics.
For the Belgian, the defeat does not erase the quality she has shown in the season and career so far, but it confirms how demanding it is to play against Osaka when the Japanese player finds her service rhythm early. On grass, reaction time is reduced, and every shorter return can be punished with the very next shot. During the match Mertens constantly had to balance between retreating deeper for defense and moving into the court to take the initiative, but Osaka did not give her enough stable balls on which she could build pressure. Because of that the match developed in a direction that suited the stronger and more direct player more. The result in two sets was not the consequence of one bad game, but of a series of small advantages that Osaka turned into control of the scoreboard.
What the victory means for the rest of the week
By advancing to the quarterfinals, Osaka secured the continuation of her appearance in the final stage of the tournament played immediately before Wimbledon. According to the official WTA draw available on June 24, 2026, her next opponent comes from the part of the draw in which Ekaterina Alexandrova and second seed Mirra Andreeva are placed. This means that in the next round a different type of challenge awaits her, depending on the final outcome of that duel: Alexandrova can bring a strong and flat rhythm, while Andreeva generally offers a more varied repertoire, speed of changing direction and tactical maturity beyond her years. Osaka will, regardless of the opponent, try to maintain the same pattern that brought her victory against Mertens: a high percentage of quality first shots, control with the forehand and short periods without mistakes. If that plan remains stable, her appearance in Bad Homburg could become one of the most important signals of her form before Wimbledon.
The 6:3, 6:3 victory therefore has greater value than mere passage to the quarterfinals. It shows that Osaka on grass can again connect power and efficiency, that she can close sets without unnecessary prolonging and that against an experienced opponent she can remain calm after a short surge from the other side of the net. Bad Homburg is a tournament played under the pressure of the proximity of a Grand Slam, but also with a clear sporting reward because the WTA 500 level brings points, a strong draw and a relevant test of form. Osaka used precisely that opportunity against Mertens: she did not only go through, but sent a clear message that grass suits her at this moment. The next match will show whether she can maintain the same level against an opponent who will enter the quarterfinals with her own ambitions and a fresh rhythm.
Sources:
- WTA - report on Naomi Osaka's victory over Elise Mertens in Bad Homburg, including the result, match duration, statistics and context of the first quarterfinal of the season (link)
- WTA - official draw of the Bad Homburg Open powered by Solarwatt 2026 tournament and overview of matchups by rounds (link)
- WTA - tournament guide for Bad Homburg 2026 with dates, competition format and round schedule (link)
- Bad Homburg Open - official information about the tournament, location, WTA 500 status and staging at TC Bad Homburg (link)
- WTA - official profile of Naomi Osaka with data on her career, titles, ranking and return after maternity leave (link)
- WTA - official profile of Elise Mertens with data on her career, singles and doubles successes (link)
- Wimbledon - official schedule of The Championships 2026, including the dates from June 29 to July 12 (link)