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

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?

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

The outcome was eyebrow-raising because of the wide gulf in experience and accomplishments between the two players at Margaret Court Arena.

Teenage Californian Tien took the opening two sets of his second-round match against former US Open champion Daniil Medvedev.

Learner Tien achieved an unprecedented feat in the past 20 years following his stunning victory over Daniil Medvedev in the second round of 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, a 19-year-old qualifier from California, became the youngest American man to reach the Australian Open's third round since Pete Sampras in 1990, upsetting a racket-tossing Daniil Medvedev 6-3,

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

In the Australian Open Round of 64 on Wednesday, we have a matchup featuring No. 5-ranked Daniil Medvedev against No. 121 Learner Tien.In Tien’s most recent competition, he fell to Arthur