(Reuters) -Third seed Iga Swiatek reached the Cincinnati quarter-finals with a 6-4 6-4 win over Sorana Cirstea on Wednesday, while Alexander Zverev needed just one game to complete victory over Brandon Nakashima before rain halted play again.
Wimbledon champion Swiatek extended her perfect record against Cirstea to 5-0 and will next face the winner of an all-Russian clash between Anna Kalinskaya and Ekaterina Alexandrova.
"We played many tough matches, so I know Sorana can really hit the ball well,
especially on faster surfaces," Poland's Swiatek said.
"I'm happy I was solid enough. I was trying to be proactive with my serve, not many of my first serves went in, but I was happy I was solid on my second serves."
Fellow Pole Magda Linette upset fourth seed Jessica Pegula 7-6(5) 3-6 6-3 in a third-round match that extended over two days after Tuesday's suspension due to rain.
The American had levelled the match at a set apiece, but on Wednesday's resumption Linette earned the break before closing it out on serve for her second Top-10 win of the season.
In the men's draw, Zverev completed a 6-4 6-4 win over Nakashima after the match was suspended overnight when he was leading 5-4 in the second set.
The German third seed is set to return to the court later on Wednesday, aiming to avenge last week's Toronto semi-final loss to Russian Karen Khachanov.
Earlier, seventh seed Holger Rune advanced after home favourite Frances Tiafoe was forced to retire with a back injury.
(Reporting by Janina Nuno Rios in Mexico City, editing by Pritha Sarkar)