The 19-year-old who was a late qualifier to the Grand Slam secured the biggest win of his young career on Thursday

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

American teen Learner Tien pulled off the biggest upset so far at the 2025 Australian Open, ousting Russian Daniil Medvedev -- the No. 5 player in the world -- in a 4-hour, 49-minute thriller at Margaret Court Arena.

“The AO is something that connects really well with New Balance because the mix of sport and culture they have is incredible,” Evan Zeder, New Balance director of global sports marketing for tennis, tells me. “I think the AO is a perfect mix and it is just a big party.”

Highlights of the fifth day of the Australian Open on Thursday (all times GMT): 1554 TEENAGER TIEN STUNS MEDVEDEV American qualifier Learner Tien held his nerve in a battle that lasted four hours and 49 minutes to stun Russian fifth seed Daniil Medvedev,

Australian Open is showcasing a crop of young men's players who are better equipped for the changes in tennis than their elders.