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

By Ian Ransom MELBOURNE (Reuters) -Teenage qualifier Learner Tien became the youngest man to reach the Australian Open fourth round in 20 years as the future of American tennis lit up Melbourne Park on Saturday.

Two of four American men still playing in Melbourne, Irvine native Tien, 19, and Aliso Viejo native Michelsen, 20, became friends on the youth tennis circuit

Learner Tien pulled off a massive upset against Daniil Medvedev at the Australian Open. So, who is Tien, the 19-year-old out of California?

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.

Watch the match highlights between Alex Michelsen & Alex de Minaur in Round 4 of the 2025 Australian Open Men's Singles Tournament Tennis.

Alex de Minaur has reached the Australian Open quarter-finals for the first time, setting up an epic last-eight match with world no.1 and reigning champion Jannik Sinner.