One other day, one other teenager ousting a top-10 participant on the 2025 Australian Open. That has been the theme of the 12 months’s first main, with Brazilian Joao Fonseca defeating No. 9 Andrey Rublev, Czech teenager Jakub Mensik ousting No. 6 Casper Ruud, and now, American teenager Learner Tien taking down No. 5 Daniil Medvedev.
Of the three upsets, Tien’s win over Medvedev was the largest given the latter’s accomplishments — a three-time Australian Open finalist, former World No. 1 and 2021 U.S. Open winner.
Tien, 19, is the youngest American to beat a top-5 participant at a grand slam since Pete Sampras in 1990. Sampras was additionally the final American teenager to succeed in the third spherical on the Australian Open 35 years in the past.
