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.
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.