Guo Hanyu hits a forehand return to Katie Volynets on her way to reaching the last 16 of a WTA 1000 event for the first time.

Aryna Sabalenka reacts after a point against Ann Li during their WTA Wuhan Open second-round match on Wednesday.

WUHAN — A frustrated Aryna Sabalenka suffered a second successive early tournament exit, as her bid for a fourth Wuhan Open title was foiled by American world No 31 Ann Li 3-6, 6-4, 7-6 (5) in round two, while China's Guo Hanyu advanced to the round of 16 on Wednesday.

The top-seeded Sabalenka fell to Nikola Bartunkova in the third round at the China Open last week and squandered a 6-3, 4-2 lead against Li to stumble at her very first hurdle in Wuhan.

The Belarusian four-time major winner lost her No 1 ranking to Elena Rybakina last month and has not won a title since March.

Playing with protective taping around her right knee, Sabalenka was in control of the match until Li swung the momentum in her direction halfway through the second set.

Sabalenka asked for the trainer when she was broken early in the decider and appeared to be struggling with her movement. Still, she was able to wipe a 2-5 deficit, saving nine match points along the way.

Li steadied the ship, though, and finished the job in two hours and 27 minutes on her 10th opportunity, setting up a last-16 clash with Indonesia's Janice Tjen.

"I think on some of those match points, I was about to lose my mind. I was about to crash out. In the end, you just have to realize, I didn't play badly and she just played really well," Li said. "And, so, you have to just play point by point. I knew that, if I stayed there, I could get to the situation again.

"For me, it just shows that I'm trying to improve every day from every match. My only goal was to improve from the last match I played," Li added. "I know that if I play my tennis and I stay positive, and I stay physical and intense, I can win any match."

Guo makes history

China's Guo outlasted Katie Volynets of the United States 6-4, 4-6, 7-6(3) to reach the last 16 at a WTA 1000 event for the first time.

"It was another very tough match today, and the score stayed close," Guo said. "Until the last point, there was no way to say the match was over, so I just tried to give everything I had from start to finish and do the best I could. I'm happy to have won another match."

Guo next plays fifth-seeded Elina Svitolina of Ukraine.

"It will be an even harder match, and I will prepare more tonight," Guo said. "The first thing is to recover well, so that I can step on court tomorrow at 100 percent."

Meanwhile, second-seeded Jessica Pegula, the runner-up in Wuhan last year, was also sent packing.

The American suffered a 2-6, 7-6(7), 6-3 upset at the hands of Jelena Ostapenko, wasting three match points along the way.

Ostapenko is the first player to beat Pegula in her opening match at a WTA 1000 event since Indian Wells two and a half years ago, snapping Pegula's 22-event winning streak in openers at this level.

Earlier, six-time Grand Slam champion Iga Swiatek launched her Wuhan Open campaign by triumphing 6-2, 6-1 in an all-Polish battle against lucky loser Magdalena Frech.

Swiatek posted her 40th victory of the season in one hour and 42 minutes and no longer has Sabalenka as a potential roadblock in the quarterfinals.

"We know each other pretty well, so I just wanted to focus on being consistent and playing as well as possible," Swiatek, the seventh seed, said of Frech.

"I know she is always running to every ball and sometimes using the power of the opponent, so I wanted to not play too crazy but play solid and I'm happy that I did that," said Swiatek, who is chasing a qualification spot for the year-end WTA Finals.

Wimbledon finalist Karolina Muchova weathered a three-hour storm to come through 3-6, 7-6 (1), 7-6(4) against American qualifier Caty McNally to extend her record in tiebreaks this season to a perfect 10-0.

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