There are three American men aged 23 and under in the second week of a Grand Slam. That hasn't happened since 2003

Learner Tien, a 19-year-old from California, became the youngest American man to reach the Australian Open's third round since 1990, upsetting No. 5 Daniil Medvedev in five sets.

At the age of 19, Learner Tien defeated Daniil Medvedev in a five-set thriller that finished just before 3 a.m. in Melbourne.

Alex De Minaur kept the home flag flying at the Australian Open as he beat rising American Alex Michelsen 6-0 7-6(5) 6-3 to reach the quarter-finals for the first time on Monday. The 25-year-old has now reached the last eight at every Grand Slam and will face top seed and defending champion Jannik Sinner for a place in the semis.

Alex de Minaur's Australian Open fourth-round opponent Alex Michelsen has a hip injury he received a medical timeout for in his previous match.