A 19-year-old Vietnamese-American tennis player surpasses a top 10 world star, achieving an unprecedented milestone in his career.

Entering the deciding set, an unexpected event occurred: Musetti, trailing 0-3, had to retire due to injury. The match concluded 4-6, 6-3, 3-0 in favor of Tien, marking the fourth retirement at this year’s China Open and raising concerns about athletes’ physical condition.

For Tien, however, this is a significant milestone: the first time he has reached the semifinals of an ATP Tour event in his career.

At just 19, Tien has had an outstanding season. Last August, he reached his career-best ATP singles ranking of No. 48. His 2025 record currently stands at 19 wins and 20 losses, including multiple wins over top 10 players, such as surprising victories against Daniil Medvedev and Alexander Zverev.

Tien also reached the fourth round of the Australian Open and the round of 16 at the National Bank Open. Now, he has taken another step forward — making his debut in the China Open semifinals.

Moreover, with this victory, Tien is assured of maintaining a top 50 ATP ranking once the standings update. At the China Open, he has gained 200 ranking points and could increase that to 330 points if he defeats the strong-seeded Medvedev in the semifinals. This demonstrates that the young player’s goals are steadily becoming reality.

Last month, during an interview with CLAY Tennis magazine, Learner Tien openly expressed his ambition: "I want to become a great tennis player. I want to accomplish great things in this sport."

When asked about the meaning of his name "Learner," he chuckled: "My mom sometimes jokes that she named me that hoping I’d always be someone who keeps learning. And I think I’m doing quite well at that. People often tease and play on words, but I find it amusing."

At that time, Tien was ranked 55th in the world, inspired by following Roger Federer in the late stage of his career and admiring Carlos Alcaraz — the new star of tennis. Now, the 19-year-old’s dream is gradually coming true. He has become the youngest player to reach the China Open semifinals since Rafael Nadal in 2006 — also at age 19. A memorable milestone that also sets up the next big showdown.

His next opponent is Daniil Medvedev. Notably, Tien has previously defeated this former world No. 1. Earlier this year at the Australian Open, Tien shocked the tennis world by beating Medvedev — the 2021 US Open champion — in a dramatic five-set match: 6-3, 7-6, 6-7, 1-6, 7-6.

At that time, Tien candidly admitted: "Confidence is a key factor in achieving success and victory. I always step onto the court believing I have a chance. I didn’t treat that match as more important than any other before. I just wanted to go out, enjoy it, and see what I could do."

Now, the setting has changed: a bigger stage, greater pressure, and brighter lights. The question is: can Learner Tien replicate that courageous performance against Medvedev in Beijing?