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

Two friends from California, Learner Tien and Alex Michelsen, have both reached the fourth round at the Australian Open. Tien is 19, and Michelsen is 20.

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.

Learner Tien has stunned the tennis world, claiming an upset victory over Daniil Medvedev at the Australian Open.

Learner Tien, a 19-year-old qualifier from California, notched the biggest upset of the 2025 Australian Open to date by beating No. 5 seed and 2024 finalist, Daniil Medvedev, in five sets. Tien won 6-3,

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?

The 19-year-old Learner Tien became the youngest player since Rafael Nadal in 2005 to reach this stage of the men's singles at Melbourne Park but fell just short of reaching the quarter-finals

Learner Tien has become the youngest American man to reach the Australian Open’s third round since Pete Sampras in 1990.

Corentin Moutet (No. 69 ranking) will face Learner Tien (No. 121) in the Round of 32 of the Australian Open on Friday, January 17.Moutet heads into the Round of 32 after winning in four sets, 4-6,

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