China's Zhang Shuai beat former world No.1 Naomi Osaka from Japan 6-4, 7-5 in the first round of the Cincinnati Open on Tuesday.

In the process, Zhang leveled their head-to-head record to three wins apiece. In the pair's previous meeting in 2018, Osaka defeated Zhang 3-6, 6-4, 7-5 in the China Open quarterfinal.

While Osaka has suffered from Achilles and back injuries this season, Zhang has had a good run, clinching her third singles title in Lyon and a doubles title in Nottingham.

"Naomi she is amazing but I don't know she is maybe not really feeling good today," Zhang said after the match. "But for sure today… not her best today."

Zhang will next face Russian Ekaterina Alexandrova who eliminated 13th-seeded Canadian Leylah Fernandez, U.S. Open runner-up from last year, 6-4, 7-5.

Fernandez's conqueror at Flushing Meadows in 2021, Emma Raducanu from the UK, remains in contention in Cincinnati with a spotless 6-4, 6-0 victory over 23-time Grand Slam winner Serena Williams who announced retirement after what Cincinnati leads up to, the U.S. Open.

"[This] may be one of the last opportunities I get to play her," Raducanu said.

"You have to cherish the moment, and you're going to have this memory for the rest of your career. I was just really trying to make the most out of every single point out there and give myself the best memories of when I played Serena once."

Raducanu, 19, will face another big name in the second round, former world No.1 Victoria Azarenka from Belarus.

(With input from Reuters)