Zverev in Halle missed out on the final after an unusual insulin problem: Fritz came from behind to secure an all-American showdown
Alexander Zverev failed to reach the final of the ATP tournament in Halle, and his defeat to Taylor Fritz in Saturday's semifinal gained additional weight after the German tennis player explained the health problems that had affected him from the very beginning of the match. Fritz defeated the top seed 6:7(4), 6:4, 7:5 in the semifinal of the Terra Wortmann Open, an ATP 500 grass-court tournament in Halle, Westphalia. According to the official ATP Tour report, the match lasted two hours and 39 minutes, and the American player hit 19 aces and won 87 percent of points behind his first serve. For Zverev, it was a painful end to a week in which, according to the ATP and the tournament organizers, he competed as the reigning Roland Garros champion and reached the semifinal on a ten-match winning streak. For Fritz, the victory meant a place in the final against Frances Tiafoe and the continuation of an exceptionally successful run against a player who was seeking his first grass-court title in Halle.
An incorrect sensor reading changed the course of the match
The most important detail after the match was not only the result, but Zverev's explanation that he entered the encounter with seriously disrupted blood sugar regulation. According to a statement reported by the tournament organizers and the German agency dpa, Zverev, who lives with type 1 diabetes, said that shortly before the start of the match his sensor showed an extremely high blood sugar level. Because of that reading, he said, he injected too much insulin, although by his own feeling he already had the impression at that moment that his sugar was low. After an additional check he realized that the reading did not correspond to the actual situation, but by then he already had to react in order to prevent hypoglycemia. According to dpa's report, in the first 45 minutes of the match he had to consume almost 350 grams of sugar, mostly through glucose gels, which he described as an experience that made him feel “terrible”.
Zverev said after the match that in the second set he was physically far from the required level, and that in the third it was also very difficult for him to maintain intensity. The tournament organizers reported his statement that the back problem, which also appeared during the match, was not the main reason for the drop, but that the blood sugar problems were more decisive. The German tennis player explained that he has used the sensor for years and that, according to him, he had never previously experienced such a drastically incorrect reading. In a match on grass, where points are often decided in short exchanges and where the serve has especially great importance, even a small drop in physical stability can change the rhythm. In Halle, this was visible in moments when Zverev tried to shorten points, rely on the opening shot and reduce the number of long rallies.
Heat, back problems and a medical timeout further complicated the semifinal
The match was played in demanding conditions, and the tournament's official website described it as a semifinal marked by intense heat in the OWL Arena and frequent use of ice towels during changeovers. Zverev took a 3:1 lead in the first set, but Fritz quickly came back and leveled at 3:3. Already in that part of the match it was visible that the German player was not moving with his usual ease; the organizers stated that he was breathing heavily, sitting down on the bench and, in the eighth game, left the court for a medical timeout. According to Bild's report, Zverev later explained that his back had “locked up” and that he used the break to receive treatment in the locker room. Still, upon returning he managed to stabilize his serve and make a mini-break in the first-set tie-break that gave him the lead.
That first set won could have created the impression that Zverev had found a way to survive a difficult day, but the second part of the match showed a different picture. Fritz stayed calm, waited for his opponent's intensity to drop and in the tenth game of the second set secured the key break for 6:4. After that came a cooling break, which further underlined how demanding the conditions on court were for both players. In the deciding set there were no major return opportunities for a long time, but at 5:5 Fritz put pressure on Zverev's serve and reached the break. The American then closed out the match, while Zverev in the closing stages was left without the necessary explosiveness and precision at the net.
Fritz continued his streak against Zverev and confirmed his status as one of the best grass-court players
Fritz's victory was not an isolated result, but the continuation of a streak that has become particularly uncomfortable for Zverev. The ATP Tour reported that with this win the American tennis player reached his seventh consecutive victory in their head-to-head meetings and took a 10:5 lead in their official Head2Head series. Fritz said after the match that he felt Zverev was struggling, but that he did not know exactly what was happening, and that this made it psychologically harder for him to find his rhythm. The tournament organizers reported his assessment that such circumstances can make a match tense because the opponent, aware of physical limitations, often plays more aggressively and shortens points. Despite that, Fritz was more stable in the decisive games, especially on serve, and took advantage of the opportunity that opened up for him late in the third set.
According to the ATP, Fritz reached his fifth ATP 500-level final in Halle and became only the second player since 2015, since Stuttgart and Halle have both been grass-court tournaments, to reach the final at both events in the same season. The organizers of the Terra Wortmann Open stated that Fritz had already played the final in Stuttgart a week earlier, where he lost to Ben Shelton, and that in Halle he was seeking another attempt at a grass-court title. The ATP also emphasized that the American is the leading player on the Tour this decade by number of wins on grass. That statistic explains why Fritz, although he was not the highest seed in Halle, looked like one of the most dangerous players in the draw in the final stages of the tournament. His combination of serve, flat shots and ability to remain calm in tie-breaks comes especially to the fore on a fast surface.
Zverev again without a title in Halle
For Zverev, the defeat also carried symbolic weight because the title in Halle remains one of the goals that continues to elude him. The tournament organizers recalled that he had twice played the final, in 2016 against Florian Mayer and in 2017 against Roger Federer, but that even then he failed to win the trophy. According to dpa's report, the German player failed to win the title in Westphalia even on his tenth attempt. In his career he has won major tournaments and titles on different surfaces, but a grass-court title is still missing. This is especially relevant in the week before Wimbledon, because Halle traditionally serves as one of the most important preparations for the third Grand Slam tournament of the season.
Zverev nevertheless tried to maintain a positive tone after the defeat. According to statements reported by the organizers of the Terra Wortmann Open, he said he was disappointed because he felt that his game was there, but that physically he could not show what he wanted. At the same time, he emphasized that in Halle he had found a good feeling for grass and that he hoped he would be able to carry that into Wimbledon. Such a message is important because the health problem in the semifinal could have raised questions about his readiness for London. Zverev said that he does not expect the episode with the sensor by itself to endanger him for the next tournament, but the fact that he had to react to an incorrect reading immediately before the match shows how sensitive a combination elite sport and a chronic health condition can sometimes be.
Why the situation with the glucose sensor was especially sensitive
Type 1 diabetes requires constant glucose monitoring and insulin adjustment, and in professional athletes that process is additionally complex because of exertion, adrenaline, heat, nutrition and match duration. The International Diabetes Federation states that continuous glucose monitors help people with diabetes because they provide real-time data and can warn of high or low values. The same organization, however, warns that such devices measure glucose in interstitial fluid, which means there can be a delay of several minutes compared with changes in the blood. In practice, this means that readings, especially in changing physical conditions, must be interpreted carefully. Zverev's case in Halle shows how incorrect information can have an immediate sporting and health impact when an athlete has to make decisions about insulin and carbohydrate intake quickly.
In tennis, that challenge is additionally visible because a match has no fixed duration. A player can spend less than an hour or more than three hours on court, and intensity can change from game to game. On grass, where serves and first shots are extremely important, a drop in concentration or energy does not have to be seen through long rallies; sometimes one weaker service game is enough. In Halle, Zverev became vulnerable precisely in such moments, especially in the closing stages of the second and third sets. Fritz recognized that and turned it into a result, although after the match he admitted that it is unusual to play against an opponent whom you feel is struggling, while not knowing the full cause.
All-American final and the tournament finale
With the victory over Zverev, Fritz secured the final against Frances Tiafoe, who defeated Daniel Altmaier 6:1, 6:3 in the other semifinal. According to the tournament organizers, this gave Halle its first final between two American tennis players, and a winner from the United States of America was set to lift the trophy at that tournament for the first time. Tiafoe reached the final stages after a convincing victory over Altmaier, who earlier in the week achieved one of the biggest wins of the tournament by eliminating Daniil Medvedev. The ATP stated that Fritz and Tiafoe, along with Mardy Fish in 2004, are the only American finalists in Halle history. The final match was scheduled for Sunday, June 21, the day after Zverev's dramatic defeat.
For Zverev, the focus now shifts to recovery and preparation for Wimbledon, which according to the tournament's official calendar begins on June 29, 2026 and runs until July 12. That means there is little room for longer adjustment between the semifinal in Halle and the first matches in London, but enough for an assessment of his health condition and rhythm on grass. His week in Halle ended without a trophy, but also with confirmation that he can play competitive tennis on a surface that has traditionally brought him the most question marks. What remains, however, is the fact that the semifinal against Fritz was marked by a rare combination of sporting pressure, heat, back problems and an incorrect glucose reading. It was precisely that combination that turned an ordinary defeat in the preparation week for Wimbledon into a story that goes beyond the result itself.
Sources:
- ATP Tour – official report on the Halle semifinal, the result, match statistics and Fritz's place in the final (link)
- Terra Wortmann Open – official report by the organizers on the Zverev - Fritz match, on-court conditions and the course of the semifinal (link)
- Terra Wortmann Open – official statements by Zverev and Fritz after the semifinal and the context of the all-American final in Halle (link)
- WELT / dpa – report on Zverev's problem with the sensor, insulin, sugar intake and preparation for Wimbledon (link)
- International Diabetes Federation – expert overview of continuous glucose monitoring and possible limitations of CGM devices (link)
- Wimbledon – official calendar of The Championships 2026 (link)