Qualifier Learner Tien achieved more than a personal milestone when he stunned Daniil Medvedev in the early hours of Friday morning at the 2025 Australian Open. With his 6-3, 7-6(7), 6-7(8), 1-6, 7-6(10-7) victory over the world No. 5 and three-time Melbourne finalist, the 19-year-old joined compatriot Alex Michelsen in the third round to make American tennis history.
Tien and the 20-year-old Michelsen, who upset former finalist Stefanos Tsitsipas in the opening round, are the first pair of U.S. men age 20 or younger to reach the third round at a Grand Slam event since the 2003 US Open (Andy Roddick, 20; Robby Ginepri, 20) and at the Australian Open since 1990 (Pete Sampras, 18; David Wheaton, 20). Tien is also the second-youngest American man to reach the third round at the Australian Open after Sampras in 1990.
Tien, from Irvine, Calif., and Michelsen, from Laguna Hills, Calif., are longtime friends and have trained together since 2021. They recently competed in the semifinals of the Next Gen ATP Finals, with Tien winning in five sets at the Jeddah youth showcase in December.
In a nearly five-hour match against Medvedev, Tien missed out on a match point in the third-set tiebreak before regrouping to prevail in a dramatic final set. He saved three break points in the opening game of the final frame before twice trading breaks with Medvedev down the stretch. Tien surrendered a 3-1 advantage early in the fifth set, then later denied Medvedev's attempt to serve out the match after being broken at 5-5.
Down a mini-break at 6-7 in the decisive tiebreak, Tien won four straight points to clinch victory, finishing the set with 13 winners.
"I was definitely hoping it wouldn't go to a fifth-set breaker, but I'm just happy to get a win,” said the American, who is set to break into the ATP's Top 100 behind his Melbourne run. “I know I made it a lot harder than maybe it could have been... Losing the third was tough after playing for that long and having a match point. I didn't even get to touch the ball I don't think, it was an ace. So it was a little disappointing to see a fourth [set] after fighting back from a break down in the third.
"Honestly in the fourth set I just had to pee so bad, so I was trying to finish it up fairly quick. But I also wanted to start the fifth serving, so I scrapped that game at 0-5, and it all worked out."
Tien's rock-solid baseline game—not dissimilar to that of 2021 US Open champ Medvedev—frustrated his world No. 5 opponent throughout the marathon match, which finished at 2:55 a.m. Friday morning in Melbourne. Backing up his consistency, the 19-year-old also displayed plenty of firepower to hit through Medvedev's defenses at crucial moments.
Tien competed in the US Open main draw each of the past three years and has now picked up his first two Grand Slam wins in five sets. He defeated Camilo Ugo Carabelli in the opening round before his statement result against Medvedev.
The California native, who had a brief playing stint at the Univeristy of Southern California in 2023, won the USTA Boys' 18s national championship in consecutive years in 2022-23 and produced a 28-match winning streak at USTA Pro Circuit events in 2024.
After notching his first Top 5 win, the American will next face Frenchman Corentin Moutet in the third round. He and Michelsen (vs. 19th seed Karen Khachanov) are joined by fourth seed Taylor Fritz (vs. Gael Monfils), 12th seed Tommy Paul (vs. Roberto Carballes Baena), 21st seed Ben Shelton (vs. Lorenzo Musetti) and Marcos Giron (vs. top seed Jannik Sinner) in the last 32.
For more from Melbourne, including full draws and schedule, visit the official Australian Open website.
