This article is part of The Next Generation series. As the greats, such as Roger Federer, Serena Williams and Rafael Nadal, become the past and Carlos Alcaraz and Iga Swiatek handle the present, The Athletic explores the next generation: the rising stars who will be tasked with securing tennis’ future.
NEW YORK — It’s the Sunday before the U.S. Open and Learner Tien is engaged in an intense practice session with a fellow American, the world No. 16 Sebastian Korda.
Long rallies. Volleys. Overhead smashes. Serves. A complete session, hours before the opening round of a Grand Slam tournament — an opportunity tennis players covet as they grow up and work their way through training, coaches, and then the tours.
Beside Tien on Court 5 was Dominic Thiem, practicing before the final slam of his career. The 2020 U.S. Open champion drew more fans and cheers from an assembly of fans; the seats surrounding Court 4, where Tien and Korda practiced, were more sparsely filled.
If Thiem is a household name, Tien is one to learn. The Irvine, Calif., native is having a career year. He won his first Challenger title at the Cranbrook Classic last month. He recorded his first match wins on the ATP Tour at the Winston-Salem Open in North Carolina, beating world No. 51 Fabian Marozsan and world N0. 68 Thiago Seyboth Wild on his way to the quarterfinals.
He also put together a 28-match winning streak between May and July and has reached a career-high world ranking of No. 191. All at the age of 18.
Learner Tien played the Open last year, losing to Frances Tiafoe. (Tim Clayton / Corbis via Getty Images)
But Tien didn’t have a professional tennis career on his horizon as a child. There was no favorite player growing up, no posters of stars hung up in his room. It was just a sport that came naturally to Tien, ever since he picked up a racket as a toddler, before twists of fate and his own talent brought him to become one of the rising American teenage tennis players.
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It started with growing up 50 yards from some tennis courts in Heritage Park, close to the Oak Creek Village neighborhood in Irvine where the family lived. Tien’s parents, Khuong and Huyen, played tennis recreationally.
“We’re hacks,” Khuong said jokingly. “We get the ball over the net inside the line.”
Khuong and Huyen, immigrants from Vietnam, brought Tien and his sister, Justice, to the courts as babies to maintain a “semblance of life.” The children are named for their parents’ professions: Khuong a real estate attorney, Huyen a school teacher. The parents would briefly hit balls before chasing their kids around the court. Eventually, Tien grabbed a racket.
It was heavy for little Tien but as he swung it, the racket’s weight would turn his wrist, making it seem like he was following through.
What was an after-dinner activity with the family turned into Tien’s sport of choice, all from the happenstance of living so close to public tennis courts.
“If courts weren’t so easily accessible, I wonder if I’d even be playing tennis,” Tien said.
Tien reached the Australian Open final in boys’ singles last year. (Darrian Traynor / Getty Images)
Khuong coached Learner during his formative years from four years old to 11. He taught him how to do the right things, the fundamentals of tennis. Tien always played with regular rackets and balls, not junior ones. Khuong involved Learner’s sister, Justice, in the practices, and he had his son hit with other groups and coaches, including local pro Chris Emery, even before thoughts of a career came along, so that it wasn’t the same voice teaching him.
Tien made sure Dad got his flowers. Whenever a coach asked Tien how he succeeded at a drill or shot as a child, he credited Khuong for teaching him.
“I just never wanted to be that guy that was screaming and yelling on the court,” Khuong said of his coaching relationship with his son.
“I see players at all levels scream out to the stands at their parents. I mean, how frustrating must it be for a player to have to do that?
“It’s knowing that they’re gonna have to sit in the same car and have dinner at the same table.”
Teaching was a “labor of love” for Khuong and Huyen, whether in a classroom or on a tennis court, because Khuong believed tennis would not become Tien’s primary career. He was home-schooled, where Huyen was the teacher, learning mathematics from a Singapore curriculum, a country ranked first in math scores according to a 2022 report from the Programme for International Student Assessment (PISA).
But tennis came easy to Tien, who learned quickly that being a lefty came with angles and assets he could exploit. There was a technical bravado on the court, even at nine years old, using serve-and-volley, putting unpredictable spins on the ball.
“He just liked making the balls do certain things,” Khuong said.
Success on the ITF and Challenger Tours has propelled the American forward. (Tim Clayton / Corbis via Getty Images)
At five, Tien won his first tournament at the Racquet Club of Irvine, before joining the U.S. Tennis Association (USTA) national development program five years later. He came up alongside several California tennis prospects, including Zachary Svajda, Brandon Nakashima and Alex Michelsen, who have joined him in this year’s U.S. Open main draw.
At 14, Tien represented the U.S. at the junior world championships. He was on a path many top junior players take: play junior Davis Cup in the mid-teens, before progressing to International Tennis Federation (ITF) tournaments, the third rung of the ATP Tour. Maybe junior Grand Slams, too.
Then the Covid-19 pandemic happened. Tennis was shut down for the year. For Tien, it was necessary. He needed a break from the sport, to be a normal teenager.
“As you get better, the obligations, the pressure, the expectations, they grow,” Khuong said. “He was tired.”
During his break, he played video games. He graduated high school — aged 15.
Then, as tennis resumed, the mindset changed. Before the 2021 Easter Bowl, an official USTA national championship, Tien told his mother that he was going to take tennis seriously. He made the final, and he qualified for his next two ITFs. Despite losing in those tournaments, Tien told his dad: “I can beat anybody now.”
During the break from tennis, players who Tien had beaten in the past were traveling to ITF tournaments around the world. He had decided he was going to beat them there, too.
“He would win matches very easily when he was young, just because he was better than other kids,” Khuong said.
“But if he wasn’t feeling well, or he wasn’t that good, he just wouldn’t work through the hardship of that match. After that (decision), it was different.”
The ascent began. At 16, Tien won the 2022 USTA Boys national championship in Kalamazoo, Mich. This earned him a wildcard into the 2022 U.S. Open, making him the youngest player to compete in the men’s singles main draw since Donald Young in 2005 — a former phenom and junior world No. 1.
He joined the University of Southern California (USC) Trojans midway through the 2022-23 NCAA college tennis season, where he went 3-0 in singles and dual matches. For USC coach Brett Masi, who saw Tien train at the Tennis Center in Carson, Calif., it wasn’t surprising. He knew he was a generational talent.
“He was 12 and beating kids five years older than him,” Masi said.
It didn’t surprise Masi to see Tien continue his rise in 2024 but that 28-match winning streak? Unimaginable back in February, when Tien fractured his rib, shelving him for eight weeks.
After that injury lay-off, as with the break from tennis in 2020, something changed in Tien. Khuong noticed an enhanced professionalism in his recovery, as he became more focused on looking after his body before and after matches.
His 28-match winning streak captured the attention of the tennis world. (Patrick Hamilton / Belga via Sipa USA)
He returned to an ITF event in San Diego in May, which he won. Little did Tien know, it was the tournament that started the streak.
During his maiden Challenger win in Bloomfield Hills, Mich., Tien won every match in three sets. In four of the five matches, Tien dropped the opening set. According to Eric Diaz, Tien’s coach, he is more even-keeled during the difficult moments of a match, clawing himself out of holes to win. The kid who would win on talent and withdraw from the grind had grown up.
“He’s such a level-headed kid,” Diaz said. “He really kept his cool in those moments, eventually building some confidence, and then it evolved into him just playing high-quality tennis.”
As their practice session ended, Korda and Tien shook hands. The crowd grew, with an appreciative applause for the players. On Tuesday, Tien plays against the No. 24 seed from France, Arthur Fils, who won his first ATP 500 title in 2024 and has progressed to the next rung of the ‘next-gen’, beating top 10 players and getting to the late stages of big ATP tournaments.
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Although his streak earned him a wildcard into the first round, this is Tien’s third U.S. Open appearance, and he’s here for a first main draw match win at Flushing Meadows. He reached last year’s boys singles final, in which he lost to Brazilian Joao Fonseca; he reached the final at the Australian Open too. Fonseca, who, like Fils, has gone on to ATP Tour success, missed out on qualifying this year.
As Tien walked off the practice court, a fan waved an American flag. In the distance, the cheers for Thiem grew louder, as the fans saluted a past Open champion on his way out of the sport, a journey so many stars have taken.
The young Tien didn’t have their posters on his wall. But another young American who picks up a racket just for fun might one day look up at his.
(Top photo: Tim Clayton / Corbis via Getty Images)
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