In a showdown between Grand Slam champions and Top 20 players, No.4 seed Elena Rybakina of Kazakhstan held off Latvia's Jelena Ostapenko 6-7(6), 6-2, 6-4 on Wednesday to make the Round of 16 at the Western & Southern Open.

Last year's Wimbledon champion Rybakina took 2 hours and 17 minutes to pull off the come-from-behind victory and edge ahead 3-2 in her head-to-head with 2017 Roland Garros titlist Ostapenko.

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This season's ace leader Rybakina fired 11 more on Wednesday to bring her 2023 total up to 392. Rybakina also converted seven of her 12 break points to overcome the 20th-ranked Ostapenko in the big-hitting meeting.

Ostapenko was unable to serve out the first set at either 5-4 or 6-5, and Rybakina used powerful forehands to build a 5-2 lead in the tiebreak.

However, Ostapenko came back from 6-3 and triple set point down, slamming a forehand return winner to grab her own set point at 7-6. All told, Ostapenko reeled off five points in a row to take the one-set lead.

In the second set, Rybakina took advantage of a pair of Ostapenko double faults to lead by a break at 3-2. Rybakina tied the match from there, after a set where Ostapenko doubled Rybakina's unforced errors by 14 to seven.

Rybakina broke Ostapenko in the first game of the third set, but Ostapenko leveled affairs at 4-4 with a winning overhead. However, Rybakina cracked a backhand return winner down the line to break for 5-4, then converted her second match point in the following game.

Rybakina will face Italian qualifier Jasmine Paolini on Thursday for a quarterfinal spot. Paolini defeated fellow qualifier Cristina Bucsa of Spain 6-1, 6-3 earlier on Wednesday.

Sabalenka survives challenge from American qualifier Li

World No.2 Aryna Sabalenka was also pushed to three sets in her opener, holding off No.192 Ann Li 7-5, 2-6, 6-4 to advance in 2 hours and 3 minutes. A semifinalist last year, Sabalenka struggled against Li's all-court game before steeling herself in the third set to wrench back control of the match and get the win.

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"It was definitely a little bit of an advantage on her side because she played a lot of matches here," Sabalenka said. "For me, it takes some time to adjust to the surface. I was really happy to win this match. She played unbelievable tennis. It was really tough today."

After a successful qualifying campaign that included wins over Lauren Davis and Alizé Cornet, Li was into her first Hologic WTA Tour main draw since Indian Wells in March. After posting a win over Australian Open semifinalist Magda Linette in the first round, the 23-year-old flummoxed Sabalenka with her attacking game style and deft hands. 

Sabalenka rebounded from the loss of the second set by keeping the pressure on Li from the baseline. Li had game point to hold to 2-1 early in the third set, but a pair of tight forehands gave Sabalenka a break chance and Li struck a double fault to hand over the game. From there, Sabalenka raced to a 5-1 before fending off Li's last comeback attempt to seal the match.

Sabalenka fends off Li in Cincinnati opener