Learner Tien (born December 2, 2005) is an American professional tennis player. He has a career-high ATP singles ranking of world No. 28, achieved on 10 November 2025 and a doubles ranking of No. 343, achieved on 18 August 2025.[1] He is currently the No. 4 American singles player.[3]
Tien was born in Irvine, California to Khuong Dan Tien and Huyen Tien, immigrants from Vietnam.[4] His first name, Learner, is inspired by his mother's profession — a math teacher.[5] His sister is named Justice after his father's profession — a real estate lawyer.[6]
Tien started taking tennis lessons in his early childhood, at a tennis facility next to his home. His potential was noticeable from the start, as he won his first tournament at the Racquet Club of Irvine at the age of 5.[6]
Junior career
Tien had a successful career as a junior, compiling a 76–23 singles win-loss record and reaching two junior Grand Slam finals, at the 2023 Australian Open[7] and the 2023 US Open, culminating with a combined ITF ranking of world No. 4.
Australian Open: F (2023) French Open: SF (2023) Wimbledon: QF (2022, 2023) US Open: F (2023)
Junior Grand Slam doubles results
Australian Open: W (2023) French Open: QF (2023) Wimbledon: 2R (2022) US Open: 2R (2022)
Professional career
2022–2023: Junior National champion, Grand Slam debut
At 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, making 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.[8] He lost in four sets to 32nd seed Miomir Kecmanović.
In August 2023, he received another wildcard to the 2023 US Open and that was his second major appearance. He lost to fellow countryman and tenth seed Frances Tiafoe in the first round.[9]
2024: First Challenger titles & ATP quarterfinal, top 125
In July, Tien also received a wildcard for the 2024 Cranbrook Tennis Classic in Bloomfield Hills, Michigan where he lifted his maiden Challenger title.[10] He became the youngest American Challenger champion since 2016, when an 18-year-old Frances Tiafoe won in Granby, Canada.[11][12] He also won the M15 in Lakewood, California, increasing his winning streak to 25.[13][14][15] 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.[16] 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.[17]
He secured a main draw wildcard for the US Open by winning the US Open wildcard challenge.[18][19][20] 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[21] 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.[22]
Tien won his second Challenger title in Las Vegas, defeating Tristan Boyer,[23] and moved up another 40 positions in the singles rankings to a new career-high of No. 151 on 16 September 2024.[24] He reached the top 125 in the rankings at world No. 124 on 14 October 2024,[25] 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.[26][27] As a result on 26 November 2024, at 18 years old, Tien qualified for the 2024 Next Generation ATP Finals.[28][29]
2025: Major, Masters fourth rounds, top 5 wins, first ATP title, top 30
Ranked No. 121, Tien made his Australian Open debut after qualifying into the main draw.[30] He defeated Camilo Ugo Carabelli in the first round for his maiden Grand Slam win.[31] 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.[32][33][34] 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.[35] His run ended with a loss to Lorenzo Sonego, in four sets.
At the 2025 Abierto Mexicano Telcel he qualified for the main draw and defeated top seed and world No. 2 Alexander Zverev, recording his biggest win by ranking, to reach his first ATP 500-level quarterfinal. He became the youngest American man to beat a Top 3 player since 2001, when Andy Roddick, who was 18 years old at the time, defeated a No. 1-ranked Gustavo Kuerten in the third round of the Canadian Masters. He was also the youngest man since 2022 to defeat a No. 3-ranked Zverev in the Madrid final, when Carlos Alcaraz, a younger 19 at the time, did it. As a result he moved into the top 70 in the singles rankings on 3 March 2025.[36][37][38]
Tien reached the fourth round of an ATP Masters 1000 for the first time in his career, at the 2025 National Bank Open, upsetting 22nd seed and local favorite Denis Shapovalov en route. He became the youngest American to reach the round of 16 at the Masters level since a 19-year-old Frances Tiafoe in 2017 Cincinnati.[39]
Tien won his first ATP Tour title at the Moselle Open after defeating Cameron Norrie, reaching the top 30 at world No. 28 on 10 November 2025.[40][41] He also became the youngest American player to lift an ATP trophy since Andy Roddick.
Playing style
Tien has demonstrated a defensive baseline play style early in his career, characterised by solid defensive retrieval, counterpunching, and astute speed and court coverage. He has a long windup on his forehand that enables him to generate height over the net and topspin; neutralising his opponent’s advantage when trying to flatten out the ball through the court. He has high fitness and consistency from the back of the court, and a dedicated point-by-point approach to wearing his opponents out with long rallies. His backhand groundstroke is comparatively flatter than his forehand; this occasionally leads to lower consistency and a few more unforced errors on that wing, but this shot of his, by contrast, is less attackable in rallies compared to his forehand which has a long windup and follow-through motion, and can be rushed by a hard-hitting opponent’s baseline power. As a left-handed tennis player, he favours both the deuce-court and ad-court exchanges with right-handed players due to his superior baseline consistency and added topspin on his forehand. However, Tien is sometimes hesitant in generating his own pace aside from in cases of easily attackable balls, especially on his backhand. He is much more adept at redirecting pace from his opponents to create offensive opportunities. In general, he hits the tennis ball with great length and limits angles in exchanges from the baseline, which allows his court coverage and fitness to outlast most opponents; who may feel compelled, due to the above factors, to over-exert against his counterpunching skills.
So far, Tien’s strategic approach in most matches is characterised by using his superior physical fitness over many opponents, limiting unforced errors from the baseline, and occasionally using his opponent’s pace against them - on occasion, he favours the backhand down the line, and there are times that he will be more aggressive than usual. Tien and coach Michael Chang have worked to improve his all-court game and offensive skills by developing a steadily improving transition/net-approach mentality. He has employed aggressive pace-generation from the baseline, net-rushing and transitioning inside the court to take time away from his opponents more often as the year has progressed. However, this has brought about mixed results.
So far, the weakest aspect of Tien’s game is his serve, by far. He hits with very generalised placement in the service box, and often not with much pace - his top speed on first serve is consistently around 100-115 mph (160-185 km/h). But he has been recorded hitting a first serve as high as 144 mph, a rarity for his standards so far.[42]
So far, Tien has demonstrated a preference for hard courts - as evidenced by his recent success on the surface. He has aimed to increase the dimensionality of his game, thereby boosting the chances of him having a breakout on the natural surfaces.
Performance timelines
Key
W
F
SF
QF
#R
RR
Q#
P#
DNQ
A
Z#
PO
G
S
B
NMS
NTI
P
NH
(W) winner; (F) finalist; (SF) semifinalist; (QF) quarterfinalist; (#R) rounds 4, 3, 2, 1; (RR) round-robin stage; (Q#) qualification round; (P#) preliminary round; (DNQ) did not qualify; (A) absent; (Z#) Davis/Fed Cup Zonal Group (with number indication) or (PO) play-off; (G) gold, (S) silver or (B) bronze Olympic/Paralympic medal; (NMS) not a Masters tournament; (NTI) not a Tier I tournament; (P) postponed; (NH) not held; (SR) strike rate (events won / competed); (W–L) win–loss record.
To avoid confusion and double counting, these charts are updated at the conclusion of a tournament or when the player's participation has ended.
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United States 
