#NextGenATP stars Joao Fonseca, Jakub Mensik and Learner Tien among the first ATP Tour champions in 2025 | ATP tour | Tennis

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#NextGenATP talents Fonseca, Mensik and Tien are the first winners of the ATP Tour in 2025

Muller, Machac, Cobolli, Brooksby, Diallo and Vacherot all feature in the nine-player list
December 11, 2025

To mark the end of another exciting season, ATPTour.com unveils our annual ‘Best Of’ series, which will reflect on the most intriguing rivalries, matches, comebacks, upsets and more. Today we’re highlighting those who have joined the winner’s circle for the first time.

The 2025 ATP Tour ushered in a new cast of new champions, nine players who have engraved their names on the winners list and in the defining story of the season. It was a year marked by unexpected breakthroughs, dramatic runs and stories that captured the imagination of fans around the world.

Alexandre Müller, Hong Kong
The Frenchman opened the new season with a nerve-wracking jump to the Bank of China Hong Kong Tennis Open title. After beating Kei Nishikori in the final, Alexandre Muller became only the third player in the Open Era to win a tour-level title after losing the opening set in every match he played (after Arthur Ashe at the 1975 WCT Finals and Alexander Bublik in Montpellier in 2024).

“I was a little tired on the courts, but I think the key was to stay calm and keep the energy to myself,” said Muller. “I stayed calm, focused on my game and tried to adapt.”

Joao Fonseca, Buenos Aires
After his triumph at last year’s Next Gen ATP Finals presented by PIF in Jeddah, Joao Fonseca arrived in 2025 full of expectations and delivered straight away. The 18-year-old produced a dazzling run at the IEB+ Argentina Open – including against Mariano Navone in the quarter-finals, where he saved two match points – to become the youngest South American champion in the ATP Tour era (since 1990).

“Incredible week, even in Argentina there are some Brazilians cheering me on,” said an emotional Fonseca. “That’s just great. Every Brazilian, everyone from his country, wants this support from his own country. For me this.” [moment] The fact that I’m alive is just incredible.”

Tomas Machac, Acapulco
Tomas Machac arrived at HSBC’s presentation of Abierto Mexicano Telcel in Acapulco as the highest-ranked player who had not yet won a title, but he left with an ATP 500 trophy in his hands. His victory in the championship match placed him alongside former Top 10 stars Tomas Berdych and Radek Stepanek as the only Czech players to win a title at that level.

“It means a lot. It’s something I never dreamed could happen, especially at an ATP 500, so it feels great for me,” said Machac, who rose five places to No. 20 with his win. “I’ve been working really hard over the past year, so I’m happy to be able to achieve something that shows I’m on the right track.”

Jakub Mensik, Miami
Facing Novak Djokovic in an ATP Masters 1000 final, almost anyone would be intimate. But not Jakub Mensik, who delivered the performance of his career at the Miami Open presented by Itau, where the 19-year-old defeated his idol in straight sets to become just the fourth man to win his first ATP Tour title at that level.

“It wasn’t the first time I played against Novak,” said Mensik, who lost his first Lexus ATP Head2Head match against Djokovic in the Shanghai quarter-finals last year. “There is no more difficult task in tennis than to beat him in the final. But of course I felt very good and it is my time, so I just tried to concentrate on the match, as I did in the previous rounds.”

Flavio Cobolli, Bucharest
Flavio Cobolli turned his 2025 season upside down in spectacular fashion at the Tiriac Open presented by UniCredit Bank. The Italian arrived in Bucharest on an eight-match losing streak at tour level, but he tore through the field – including top seed Sebastian Baez in the final – to join the ATP Tour winner’s circle.

“It’s a big dream come true for my career,” said Cobolli. “I have always dreamed of winning an ATP tournament and that happened today. I had a difficult moment. I had not won a match before this tournament this year and I won the tournament. So I am very happy with it.”

Jenson Brooksby, Houston
While Muller’s performance in Hong Kong was defined by drama, Jenson Brooksby’s week at the Fayez Sarofim & Co. US Men’s Clay Court Championship in Houston downright cinematic. The 24-year-old American saved match points in three of his matches on his way to his first title. He survived one in his first-round qualifying match, two against third seed Alejandro Tabilo in the second round of the main draw, and one against top seed Tommy Paul in the semifinals before defeating 2023 Houston champion Frances Tiafoe 6-4, 6-2 in the final. Brooksby started the season as an unranked player, but in Houston, where he competed as world number 507, he became the third lowest-ranked champion in ATP Tour history (since 1990).

“It means the world. It was one of my biggest goals since I became a professional tennis player,” said Brooksby, who entered the ATP 250 as a qualifying wildcard. “It just means a lot to have my first. It really does. It’s probably the best week of my life.”

Gabriel Diallo, ‘s-Hertogenbosch
At the Libema Open, Gabriel Diallo showed his natural feel for grass and launched 56 aces on his way to the title at the ATP 250 in ‘s-Hertogenbosch. He defeated close friend Zizou Bergs 7-5, 7-6(8) in a thrilling final before collapsing in delighted disbelief.

“Oh man, I don’t have the words for it. It’s something you dream about all your life since you were a little kid, to win an ATP Tour title,” said Diallo, who lost his first tour final in Almaty in 2024. “The fact that I was able to do it here after losing a final last year means a lot to me. I’m very happy, not only for myself but for my whole team.”

Valentin Vacherot, Shanghai
Valentin Vacherot produced one of the most astonishing runs of the season at the Rolex Shanghai Masters. As the No. 204 player in the PIF ATP Rankings, he became the lowest-ranked ATP Masters 1000 champion, beating the likes of Holger Rune and Djokovic ahead of his cousin and former Texas A&M teammate Arthur Rinderknech in a family final.

“It’s unreal what just happened. I have no idea what’s happening now. I’m not even dreaming, it’s just crazy,” Vacherot said after the final. “I’m so happy with my performance over the last two weeks. There has to be one loser, but I think today there are two winners, one family that won. And I think the story for the sport of tennis is surreal.”

Student Ten, Metz
In the final week of the regular ATP Tour season, Learner Tien provided a decisive moment at the Moselle Open in Metz. The 19-year-old added a maiden tour-level trophy to a year that saw him rack up five Top 10 wins and reach an ATP 500 final in Beijing.

“I never take it for granted, just coming here and competing. So holding this trophy really means the world to me. And I’m just very grateful,” Tien said during the trophy ceremony.