Jakub Mensik was never supposed to do this at the French Open. Not like this, not now, and definitely not after he was wheeled off the court in a wheelchair having cramped so severely after his second-round match that he could barely stand. The 20-year-old Czech is in the semifinals of Roland Garros, and he got there by beating Joao Fonseca 6-4 6-3 7-6(3) in his most dominant performance of the fortnight. Nobody in Paris looks at him the same way they did two weeks ago. They probably should not have underestimated him in the first place.
The calling card for Mensik was always there if you were paying attention. In 2025, at just 19 years old and ranked outside the Top 50, he beat Novak Djokovic in two tiebreakers in the Miami Open final, 7-6 7-6, to win his first ATP Tour title. He became the lowest-ranked champion in Miami Open history, beating Djokovic in a final that required nerves of steel. The serve was massive, the forehand a genuine weapon, and the poise under pressure, in a Masters 1000 final, against a 24-time Grand Slam champion, was remarkable. He was not supposed to win that week either.
Jakub Mensik at the 2026 French Open
Mensik’s French Open has been a study in resilience as much as talent. After edging Mariano Navone in a fifth-set tiebreaker in the second round, he collapsed to the clay after match point and required medical attention on court. “The last 20-30 minutes of the match it was just really insane,” Mensik said. “I’m happy I managed to stay mentally focused and calm.” That is a quote of someone who understood exactly what was happening to his body and refused to let it end his tournament.
From there, he only got better. He needed five sets to advance in the fourth round against Andrey Rublev, a former top-five player who had been in decent form through the first week, before turning in his best display of the tournament against Fonseca in the quarters. He won 13 of 15 serve-and-volley points against Fonseca, a player who had beaten both Djokovic and Casper Ruud in the previous rounds. “It was one of my best performances so far,” Mensik said.
The physical question had always been the asterisk next to his name. For all his gifts, the towering serve, the clean ball-striking, the hands at the net, fitness and endurance had lagged behind his technique. At 6-foot-5 and 20 years old, managing a body that size over a full best-of-five match in Paris heat was always going to be a challenge. What Mensik’s run has shown is that the work on that side of his game has been done quietly and properly. He is not just surviving the conditions. By the quarterfinal, he was controlling them.
His game right now is balanced in a way that is not always typical for big-serving attackers. The serve leads. The forehand punishes. But the movement has improved, the decision-making on clay, still not his most natural surface, has been sharp, and his tactical awareness in managing rallies against different types of opponents has been notably mature.
A Level to Go
The semifinal against Zverev is a different conversation entirely. Zverev is the second seed, the clear favorite, and the highest-ranked player left in the draw after the exits of Sinner, Djokovic. He has been to a Roland Garros final before. He has been to three Grand Slam finals. He is bigger, more experienced, and has been the best player in this draw since the exit for Sinner.
Mensik’s French Open has been extraordinary, but Zverev presents a level of opponent he has not yet faced in this tournament. The German’s ability to neutralise big serves with his return game, combined with his own aggressive baseline hitting, is the kind of problem Mensik’s serve-led attack has not been tested against this fortnight. There is a genuine question here, about whether a 20-year-old on his first deep Grand Slam run has the tools and experience to navigate a full best-of-five against the tournament favourite at this stage of development.
He will not bow out easily. That much is certain. The fight he has shown across his matches here, surviving cramps, grinding out fifth sets, recovering to produce his best tennis in the quarters, is the calling card of a player who does not know when he is beaten. Zverev will have to earn it, and Mensik will make him work for every point. But the smart money is on the German making Sunday’s final.
Verdict
Jakub Mensik has announced something the tennis world can no longer ignore: the Czech teenager, now almost 21, has arrived at the top of the game ahead of any realistic schedule. The Miami win over Djokovic was a signal. Paris is a confirmation. No longer is he a player with potential. He is a player who competes at the highest level and makes the best players uncomfortable in the process.
There are still levels to reach. His clay-court game, while vastly improved, will continue to develop. His Grand Slam experience is still limited. The mental and physical demands of a second week at a Slam, sustained over years, are things you can only learn by living through them. He is living through them now, which means he will be more equipped for them next time.
Next time, and the time after that, and the time after that. Jakub Mensik is going to be a problem for a very long time.
Main Photo Credit: Andy Abeyta/Desert Sun/USAToday Network
