NEW YORK — Zheng Qinwen is most dangerous when she is down.

For the second consecutive match, the 2024 Olympic gold medalist came back from 5-0 down in a set to win. This time, six-time major champion Iga Świątek was on the receiving end of a 7-5, 6-3 victory on Arthur Ashe Stadium, in which the 2022 U.S. Open champion’s serve failed to help her escape Zheng’s surge in the opening set.

“I guess to come back again from 0-5, that’s not lucky,” Zheng said in an on-court interview Monday, smiling. In the previous round, she came from 5-0 down to 2025 Australian Open champion Madison Keys in the deciding set, again winning 7-5.

Like a dislodged train cart rolling down a hill, Zheng started slowly and picked up speed until she became unstoppable.

Świątek flew to a 5-0 lead in the first set before Zheng seemed to remember that such a deficit is not insurmountable. She settled in and started serving better, calmly rattling off games while Świątek, flustered by the turn, struggled to raise her level to match.

Świątek had started as ominously as Zheng did slowly. She raced to her lead by playing the patient tennis that earned her the Canadian Open title, breaking the sidelines with her forehand and letting Zheng make errors on both serve and return.

But once Zheng got her teeth into the set with a brisk hold, the fundamental hole in Świątek’s game the past 12 months resurfaced. While her partnership with Francisco Roig, a longtime coach of Rafael Nadal, has brought back the controlled aggressiveness and tempo that she wants in her baseline game, she has not yet made similar adjustments on her serve.

There were signs of changes starting early at the Canadian Open, with Świątek dropping her speeds down to the late 80 mphs and early 90s and focusing more on placement, but the latter of those was missing Monday. Zheng found her range on return, and a familiar dynamic emerged: Where Zheng was playing service games in attack, Świątek was playing them at neutral or on defense.

She still had three set points, two when leading 5-1 and one when leading 5-3, but the cumulative effect of having to play so many rallies started to draw errors out of her baseline game.

Świątek turned at one point to her coach, Fransisco Roig, to ask him what she could do to staunch the bleeding. He told her to simply accept that Zheng was playing well, handling everything that Świątek threw at her without any sign of emotion or effort.

The 23-year-old said she was so focused she forgot the score at one point in the first set.

In the second set, all Zheng needed was a break. At 3-3, 30-30, Zheng rocketed a deep return that Świątek couldn’t corral and she hit a forehand wide. On the next point, Zheng hit a backhand return winner down the line and sealed the break. In the previous game, Świątek had two break points of her own, but missed a tight second-serve forehand return as if she knew that her serve was not going to give her the platform to mount a comeback.

“Little by little I found my rhythm on the center court. It’s been a long time since I played on a center court… I just focused point by point, little by little I started to play better tennis,” Zheng said.

The win is Zheng’s seventh in a row in New York. She came through qualifying, with her ranking having dropped thanks to a chronic elbow injury, and by getting to the fourth round, she earned the chance for her first win over a top-10 player since she beat world No. 1 Aryna Sabalenka at the Italian Open in May 2025.

For Świątek, the defeat means this is her first season without a major title since 2021. While she has solidified her tennis and her intensity on court since working with Roig, her serve continues to be a pressure problem for the other elements of her game.