Elise Mertens made a smooth transition from hardcourts to clay on Monday with a straight sets victory over Hsieh Su-Wei.
The No. 11 seed beat Su-Wei 6-3, 6-1 after losing out in the US Open quarterfinals to eventual runner-up Victoria Azarenka.
Mertens struck 17 winners and converter six of 11 break point opportunities.
She will face Poland's Magda Linette next who beat 2017 French Open champion Jelena Ostapenko in straight sets 6-4, 6-3.
The unseeded Amanda Anisimova edged out No. 16 seed Donna Vekic 7-6(4), 7-6(6).
No. 10 seed Elena Rybakina defeated Ekaterina Alexandrova 6-0, 6-4 in just over an hour, avenging two previous losses this year to the Russian.
The Kazakhstan player had been beaten by Alexandrova in the Shenzhen final in January and in the first round of the Western & Southern Open in August.
"I am happy because I played against her already twice," she said. "It's a different surface and of course I know how she plays, I had tactics before the match that I followed."
Rybakina will play Marie Bouzkova in the next round after she beat Ajla Tomlijanovic 6-3, 6-4.
Elsewhere, Russia's Anastasia Pavlyuchenkova beat China's Zhang Shuai 6-4, 6-7, 6-1 while Amanda Anisimova just scraped past Donna Vekic 7-6, 7-6.
Barbora Strycova will take on fellow Czech Republic player Karolina Pliskova in the next round after beating Veronika Kudermetova 6-3, 6-3.
Wildcard Jasmine Paolini set herself up with a tough next round match against No. 1 seed SImona Halep when she beat Anastasija Sevastova 6-2, 6-3.
Jill Teichmann lost 6-3, 6-3 to Anna Blinkova while Danka Kovinic only dropped one set when she beat Julia Gorges 6-1, 6-0.