American youngster Learner Tien advanced to the Australian Open quarterfinals for the first time by thrashing former world No. 1 Daniil Medvedev 6-4, 6-0, 6-3 in the fourth round. The 20-year-old became the youngest man to reach this stage at Melbourne Park since Nick Kyrgios in 2015. Tien now faces third seed Alexander Zverev for a semifinal spot.
Learner Tien, a 20-year-old left-hander from Irvine, California, produced a tactical masterclass to defeat three-time Australian Open finalist Daniil Medvedev in straight sets on Sunday. The 25th seed, provisionally ranked No. 24, did not drop a set in the match, securing his place in the quarterfinals as the youngest American man to reach the final eight at a Grand Slam since Andy Roddick in 2002.
Former top-20 player Nicolas Escude praised Tien's approach, calling it "absolutely perfect in his tactical mastery." Escude noted that Tien varied his shots relentlessly, never delivering the same ball twice and using his left foot to keep Medvedev off balance. "For two sets, Tien didn’t give him the same ball twice," Escude told Eurosport. "He never stopped moving him around... Daniil ended up completely missing the mark."
Tien, coached by 1989 French Open champion Michael Chang, has enjoyed a meteoric rise. Entering 2025 ranked No. 122, he finished the year at No. 28, claiming his first ATP title at the Moselle Open in November and winning the Next Gen ATP Finals in December. This marks his eighth Grand Slam main-draw appearance, where he has now doubled his career wins on the big stage to eight.
The unassuming Tien, who still lives at home with his close-knit family—parents Vietnamese immigrants Huyen (a retired teacher, after whom he is named) and lawyer Khuong (namesake for sister Justice)—remains grounded. "My parents are still very much involved in my life and I'm very grateful to them," he said post-match. He has earned over $3 million in prize money since turning professional.
Tien expressed growing confidence ahead of Tuesday's clash with Zverev, the world No. 3 and 2025 runner-up. "I feel like I have been playing a little bit better match by match... Right now I'm feeling better than I have all week," he said. As the last remaining American in the men's draw, Tien carries the hopes of US tennis into the last eight.