![\"Learner](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/11\/tien-grand-slam-upsets-2025-2.jpg\")
<\/p>\n Best of 2025
\n #NextGenATP stars Tien & Fonseca spring biggest Grand Slam upsets of 2025<\/p>\n
Gigante, Collignon, Rinderknech also feature in Top 5 list<\/p>\n
November 30, 2025<\/p>\n
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Daniel Pockett\/Getty Images<\/p>\n
Learner Tien defeats Daniil Medvedev in five sets at the Australian Open.
\n By Jerome Coombe<\/p>\n
To mark the end of another thrilling season, ATPTour.com is unveiling our annual ‘Best Of’ series<\/a>, which will reflect on the most intriguing rivalries, matches, comebacks, upsets and more. Today we highlight five standout Grand Slam comebacks from this season.<\/strong><\/p>\n Taking down a top player is one thing, but doing it on their favourite surface, in front of a packed crowd \u2014 or even in your first Grand Slam match \u2014 is something else.<\/p>\n From rising teenagers dismantling top seeds to qualifiers defying the odds on the sport\u2019s grandest stages, the 2025 majors delivered drama few could have scripted. As part of our annual season-in-review series, ATPTour.com counts down the five most unexpected Grand Slam upsets of the year.<\/p>\n 5) Roland Garros<\/a> R2: Gigante d. Tsitsipas 6-4, 5-7, 6-2, 6-4 Few expected the Italian qualifier, at No. 167 in the PIF ATP Rankings, to trouble one of the clay-court elite. But Gigante, playing with the verve and fire of someone who had nothing to lose, unleashed his explosive lefty forehand to topple the 2021 finalist in four sets. It was a loss that cut deep for Tsitsipas.<\/p>\n For the first time since 2018, the former World No. 2 and Nitto ATP Finals<\/a> champion fell outside the Top 20, and his season was later derailed by a back injury that limited him to just four more wins. Gigante\u2019s run to the third round was a defining moment, and the Italian has since risen to a career-high World No. 125 as he continues his bid for a Top 100 berth.<\/p>\n 4) US Open<\/a> R2: Collignon d. Ruud 6-4, 3-6, 3-6, 6-4, 7-5 A broken thumb had disrupted his aim of gaining direct entry to Roland Garros<\/a>, and until the US Open<\/a>, he had never won a main-draw match at a major. But, after downing Daniel Elahi Galan<\/a> in his opener, Collignon then produced the performance of his life to prevail against the 2022 finalist Casper Ruud<\/a> after three hours and 28 minutes.<\/p>\n \u201cI think it\u2019s the best day of my life,\u201d said Collignon. \u201cIt was not easy because Casper is a great champion. I was so scared at the beginning, but I found my rhythm.\u201d<\/p>\n It wasn\u2019t all straightforward for Collignon, however, as he served three double faults when serving for the match at 6-5 in the fifth before eventually converting his third match point. It was a win that catapulted him back inside the Top 100 and set him up for a strong finish to the year, during which he overcame No. 8 Alex de Minaur<\/a> in the Davis Cup and reached the semi-finals on home soil at the ATP 250 in Brussels.<\/p>\n 3) Wimbledon<\/a> R1: Rinderknech d. Zverev 7-6(3), 6-7(8), 6-3, 6-7(5), 6-4 Rinderknech slammed 79 winners with relentless aggression, taking it to Zverev from the first ball to the last to secure his maiden win over a Top 5 player. The upset became a springboard for a stunning second half of the season, which included a semi-final run in Gstaad and a fourth-round showing at the US Open<\/a>. He later reached his maiden ATP Masters 1000 final in Shanghai where, fittingly, he defeated Zverev again and improved to 2-0 in their Lexus ATP Head2Head series.<\/p>\n \u201cIt was a very important moment, probably the best tennis moment of my career,\u201d Rinderknech said in October, speaking of his Wimbledon<\/a> win against Zverev. \u201cThen several things succeeded step by step. I feel I\u2019m on the right track and I can now do what I want to do, the way I want.\u201d<\/p>\n 2) Australian Open<\/a> R1: Fonseca d. Rublev 7-6(1), 6-3, 7-6(5) Yet Fonseca used his calm aggression and heavy forehand to surge past ninth seed Andrey Rublev<\/a> in straight sets \u2014 a win that electrified Margaret Court Arena and set social media alight. For the 18-year-old Brazilian, who had triumphed at the Next Gen ATP Finals presented by PIF<\/a> four weeks prior, it was validation of months of hype following his rapid climb across the 2024 season.<\/p>\n \u201cI was trying to not put pressure on myself, playing with a Top 10 guy in a huge stadium,\u201d said Fonseca, who was backed by many Brazilian fans in Melbourne. \u201c[I was] trying to call the crowd to help me. I just enjoyed playing my game. That\u2019s one thing about myself, is that I play better in the important points, I go for my shots. That was the difference today.\u201d<\/p>\n Although Fonseca fell in his second-round match to Lorenzo Sonego<\/a>, the young talent has further proven himself across the 2025 season. He captured his maiden ATP Tour title in Buenos Aires in February and then won the crown at the ATP 500 in Basel, becoming the first Brazilian to win a title above ATP 250 level since Gustavo Kuerten<\/a> in 2001.<\/p>\n 1) Australian Open<\/a> R2: Tien d. Medvedev 6-3, 7-6(4), 6-7(8), 1-6, 7-6(10-7) Competing as the World No. 121, Tien looked destined for a heartbreak chapter rather than a breakthrough one after failing to convert a match point in the third set. The tension escalated further into the night when Medvedev stepped up to serve for the match at 6-5 in the fifth, but Tien refused to wilt, showing a blend of courage and clarity \u2014 and even shades of Medvedev\u2019s own tactical shrewdness \u2014 to claw his way back and seize the biggest win of his career at 2:54 a.m. local time.<\/p>\n You May Also Like: Rivalries of 2025: Medvedev vs. Tien<\/a><\/p>\n “I was definitely hoping it wouldn’t go to a fifth-set breaker, but I’m just happy to get a win,\u201d said Tien. \u201cI know I made it a lot harder than maybe it could have been… Losing the third was tough after playing for that long and having a match point.\u201d<\/p>\n![\"2025](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/11\/atp-awards-2025-nominees-are_728x90.gif\")
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<\/strong>Stefanos Tsitsipas<\/a> had turned Roland Garros<\/a> into one of his happiest hunting grounds, until Matteo Gigante<\/a> kicked the doors down.<\/p>\nMatteo Gigante” style=”width:100%;” src=”https:\/\/www.atptour.com\/-\/media\/images\/news\/2025\/11\/18\/14\/09\/gigante-roland-garros-2025-upsets.jpg?w=100%25″>Matteo Gigante<\/a> earns his first Top 20 win over Stefanos Tsitsipas<\/a> at Roland Garros<\/a>. Photo: Adam Pretty\/Getty Images.<\/p>\n
<\/strong>For Raphael Collignon<\/a>, New York became the city where promise met proof.<\/p>\nRaphael Collignon” style=”width:100%;” src=”https:\/\/www.atptour.com\/-\/media\/images\/news\/2025\/11\/18\/14\/29\/collignon-us-open-2025-upsets-2.jpg”>Raphael Collignon<\/a> reaches the third round at a major for the first time. Photo: Matthew Stockman\/Getty Images.\u00a0<\/p>\n
<\/strong>After four hours and 44 minutes on Centre Court, Arthur Rinderknech<\/a> delivered the moment that would change the rest of his 2025 season. The Frenchman\u2019s opener against third seed Alexander Zverev<\/a> at Wimbledon<\/a> had all the makings of a mismatch, but he refused to play the part of underdog.<\/p>\nArthur Rinderknech” style=”width:100%;” src=”https:\/\/www.atptour.com\/-\/media\/images\/news\/2025\/11\/18\/14\/05\/rinderknech-wimbledon-2025-upsets.jpg”>Arthur Rinderknech<\/a> defeats Alexander Zverev<\/a> in five sets at Wimbledon<\/a>. Photo: Corinne Dubreuil.<\/p>\n
<\/strong>Joao Fonseca<\/a> arrived at the Australian Open<\/a> as one of the Tour\u2019s most exciting prospects, but few expected him to out-hit one of the sport’s fiercest ballstrikers in his first main-draw match at a major.<\/p>\nJoao Fonseca” style=”width:100%;” src=”https:\/\/www.atptour.com\/-\/media\/images\/news\/2025\/11\/18\/14\/16\/fonseca-melbourne-2025-upsets.jpg”>Joao Fonseca<\/a> beats Andrey Rublev<\/a> in straight sets at the Australian Open<\/a>. Photo: William West\/Getty Images<\/p>\n
<\/strong>Margaret Court Arena played host to two of the season\u2019s biggest shocks, and American teenager Learner Tien<\/a> delivered the second with his marathon, late-night victory over three-time Australian Open<\/a> finalist Daniil Medvedev<\/a>.<\/p>\nLearner Tien” style=”width:100%;” src=”https:\/\/www.atptour.com\/-\/media\/images\/news\/2025\/11\/18\/14\/20\/tien-melbourne-2025-upsets.jpg”>Learner Tien<\/a> defeats Daniil Medvedev<\/a> in five sets at the Australian Open<\/a>. Photo: Paul Crock\/Getty Images.<\/p>\n