The 19-year-old who was a late qualifier to the Grand Slam secured the biggest win of his young career on Thursday

Learner Tien, a 19-year-old qualifier from California, notched the biggest upset of the 2025 Australian Open to date by beating 2024 finalist and No. 5 seed, Daniil Medvedev in five sets, 6-3, 7-6(4),

Learner Tien, a 19-year-old qualifier from California, became the youngest American man to reach the Australian Open's third round since Pete Sampras in 1990, upsetting Daniil Medvedev in five sets on Thursday.

Defending champion Jannik Sinner's consecutive-sets streak ended in the second round of the Australian Open on Thursday night, but he advanced with a 4-6, 6-4, 6-1, 6-3 victory over wild-card entry Tristan Schoolkate.

Defending champ Jannik Sinner drops set for first time since October, but rallies for win; American Danielle Collins plays villain while advancing.

Jannik Sinner has announced that he will part ways with his coach Darren Cahill at the end of the season. The Australian, who joined Sinner's team in July 2022, will conclude the 2025 campaign before stepping back from full-time tennis.

Australian Open is showcasing a crop of young men's players who are better equipped for the changes in tennis than their elders.

Highlights of the fifth day of the Australian Open on Thursday (all times GMT): 1242 PAOLINI EASES PAST ZARAZUA Last year's French Open and Wimbledon finalist Jasmine Paolini brushed aside Mexico's Renata Zarazua 6-2 6-3 to reach the third round,

Iga Swiatek, of Poland, plays a backhand return to Rebecca Sramkova, of Slovakia, during their second round match at the Australian Open on Thursday in Melbourne.