Learner Tien (born December 2, 2005) is an American professional tennis player. He has a career-high ATP singles ranking of world No. 80 achieved on January 27, 2025 and a doubles ranking of No. 722 achieved on February 3, 2025.
Tien was born in Irvine, California to Vietnamese parents Khuong Dan Tien and Huyen Tien.[3] His first name, Learner, is inspired by his mother's profession — a math teacher.[4] His sister is named Justice after his father's profession — a real estate lawyer.[3]
Tien started playing tennis when he was just a toddler, and won his first tournament at the Racquet Club of Irvine at the age of 5.[3]
Tien had a successful career as a junior, compiling a 76–23 win-loss record and reaching two junior Grand Slam finals, at the 2023 Australian Open[5] and the 2023 US Open, culminating with a combined ITF ranking of world No. 4. In doubles compiling a 36–18 win-loss record and winning the 2023 Australian Open, partnering Cooper Williams.[5]
At just 16 years old, Tien won the 2022 USTA Boys 18s National Championship, which earned him a wildcard into the main draw of the 2022 US Open. This made him the youngest player to compete in the men’s singles main draw at the US Open since a then-16-year-old Donald Young (also the champion at Kalamazoo) played in the 2005 US Open, and also the first player aged 16 to compete since Zachary Svajda in 2019.[6] He lost in four sets to 32nd seed Miomir Kecmanović.
In July, Tien also received a wildcard for the 2024 Cranbrook Tennis Classic in Bloomfield Hills, Michigan where he lifted his maiden Challenger title.[8] He became the youngest American Challenger champion since 2016, when an 18-year-old Frances Tiafoe won in Granby, Canada.[9][10] He also won the M25 in Lakewood, California, increasing his winning streak to 25.[11][12]
At the end of July, a week later, he again made the quarterfinals at the 2024 Chicago Men's Challenger and reached the top 250 in the rankings on 29 July 2024. He reached his second Challenger semifinal of the season, defeating eight seed Hong Seong-chan.[13] He lost to Yunchaokete Bu, ending a 28-match winning streak across ITF and ATP Challenger tournaments. A week later, he also made the quarterfinals at the 2024 Lexington Challenger but lost to Hugo Grenier.[14]
He secured a main draw wildcard for the US Open by winning the US Open wildcard challenge.[15][16][17]
Ranked No. 231, Tien qualified for the main draw at the 2024 Winston-Salem Open. There he defeated fellow qualifier Tristan Schoolkate and upset ninth seed Fábián Marozsán[18] and Thiago Seyboth Wild to record his first three ATP Tour wins and reach his first ATP quarterfinal. He became the youngest American ATP tour-level quarterfinalist since Brandon Nakashima in 2020 (in Delray Beach). As a result he climbed 40 positions in the singles rankings to world No. 191 on 26 August 2024.[19]
He won his second Challenger title in Las Vegas, defeating Tristan Boyer,[20] and moved up another 40 positions in the singles rankings to a new career-high of No. 151 on 16 September 2024.[21] He reached the top 125 in the rankings at world No. 124 on 14 October 2024,[22] following another title at the Fairfield Challenger after playing a 39-minute final, the shortest championship match in Challenger history, against Bernard Tomic. He became the fourth American to win three ATP Challenger Tour titles before his 19th birthday after Taylor Fritz, Andy Roddick and Sam Querrey.[23][24]
As a result on 26 November 2024, at 18 years old, Tien qualified for the 2024 Next Generation ATP Finals.[25][26]
2025: Australian Open debut & fourth round, top 5 win, top 100
Ranked No. 121, Tien made his Australian Open debut after qualifying into the main draw.[27] He defeated Camilo Ugo Carabelli in the first round for his maiden Grand Slam win.[28] Next, he upset fifth seed Daniil Medvedev, for his first top 10 and top 5 win, after winning the 10-point tiebreaker in the fifth set, in a 4 hours and 50 minutes match that ended at 3 am in Melbourne. At 19 years old he became the youngest American player to reach the third round of the tournament in 35 years, since Pete Sampras in 1990.[29][30][31] Tien defeated Corentin Moutet in straight sets to reach the fourth round of a Grand Slam for the first time in his career and moved into the top 100 in the singles rankings. With the win, he became the second-youngest American man to reach the fourth round at the Australian Open in the Open Era (after Sampras), and the youngest player since Rafael Nadal in 2005.[32] His run ended with a loss to Lorenzo Sonego, in 4 sets.