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

American teenager Learner Tien produced arguably the biggest shock of the Australian Open so far as he defeated last year’s runner-up Daniil Medvedev in five sets, 6-3, 7-6 (4), 6-7 (8), 1-6, 7-6 (7).

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.