The 19-year-old enjoyed a breakthrough first season on the ATP Tour. A finalist in Jeddah last December, the American showcased his level to the world in 2025. He won his first ATP Tour title in Metz and reached the final at the ATP 500 event in Beijing. Tien also advanced to the fourth round at the Australian Open and enjoyed a run to the last 16 at the ATP Masters 1000 event in Shanghai. 

The lefty recorded five Top 10 wins in 2025 and is at a career-high No. 28 in the PIF ATP Rankings, having started the season outside the Top 120. Read more about the American here.