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.

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),

Last year’s runner-up Daniil Medvedev was dumped out in the Australian Open second round early Friday morning by 19-year-old qualifier Learner Tien in a massive Melbourne shock. In his debut Australian Open,

Daniil Medvedev is out of the Australian Open after losing to American qualifier Learner Tien in the biggest upset of the tournament so far. The 28-year-old was taken all the way to a deciding set by his teenage opponent, with the match going on for nearly five hours and ending just before 3:00am.

Learner Tien takes down Daniil Medvedev in a thrilling match to advance into the next round at the Australian Open.

Inspired American teenager Learner Tien outlasted three-times Australian Open runner-up Daniil Medvedev to reach the third round with a 6-3 7-6(4) 6-7(8) 1-6 7-6(7) victory in a late-night epic on Thursday.