Learner Tien’s US Open ends in a five-set loss to Karen Khachanov

On Monday night at Louis Armstrong Stadium, Learner Tien sat under a towel after the last point and wiped his face. Karen Khachanov had just beaten him 7-5, 4-6, 6-7(6), 6-1, 6-4 in three hours and 50 minutes. The No. 14 seed from Irvine had led two sets to one. He left one win short of the US Open quarterfinals — and one win short of joining Ben Shelton, Frances Tiafoe, and Alex Michelsen as the fourth American man in that round.

For Tien, the night still closed the longest home Slam he has played. He arrived 0–4 in first rounds at Flushing Meadows. This year he beat Nuno Borges in straight sets, ended Gaël Monfils’s Grand Slam career 6-3, 6-4, 6-3, and outlasted Jakub Mensik in five — becoming the youngest American man into a US Open fourth round since Andy Roddick in 2002. The Khachanov match was his first career loss in a fifth set.

The middle of that match was the Tien who has climbed into the top 15. Trailing 4-1 in the third-set tiebreak, he won seven of the next nine points and took the set when Khachanov netted on set point. Then the Russian took over: sixteen of the first twenty-one points in the fourth, a 6-1 set, and a break for 5-4 in the fifth. Tien’s forehand sailed long on match point. Khachanov, ranked No. 50, called it a really crazy match — their first — and talked about the extra balls Tien kept sending back from outside the court.

The year around the loss is why the fourth round mattered. Tien reached an Australian Open quarterfinal in January and lost to Alexander Zverev. He won Geneva on clay in May — his second ATP title, after Metz last November — and made a Masters 1000 semifinal in Montreal before Shelton stopped him. In August he reached a career-high No. 12. He is still 20. His parents, Khuong Dan and Huyen Tien, came to the United States as Hoa refugees from Vietnam. He grew up on public courts in Irvine, spent a semester at USC, and trains with Michael Chang.

Tien is Vietnamese American, from Irvine, coached by another Southern California player who won a Slam with the same mix of speed and patience. The Flushing crowd has found him. Monday was the first time he belonged in the second week of his home Slam, and the towel over his head showed how hard it was to leave it.

Shelton, Tiafoe, and Michelsen play on without him. Tien still leaves New York with a first main-draw win, a first fourth round, and a five-set war on Armstrong. The next bar here is a quarterfinal. Away from Queens, it is whether the hard-court game that got him to an Australian Open quarterfinal keeps showing up week to week.