Top seed Novak Djokovic breezed through his third round match Thursday but world No. 2 Rafael Nadal was pushed to the limit before he reached the quarterfinals of the Cincinnati Masters.
Nadal extended his perfect record against Fernando Verdasco but needed three tiebreak sets to outlast his fellow Spaniard 7-6 (7/5), 6-7 (4/7), 7-6 (11/9) while world number one Djokovic routed Czech Radek Stepanek 6-3, 6-3 in their centre court match.
The top three in the men's draw moved on Thursday as third seeded Swiss star Roger Federer also advanced to the quarters by thumping American James Blake in the evening match, 6-4, 6-1.
Nadal next faces American seventh seed Mardy Fish, who outlasted France's Richard Gasquet, 7-5, 7-5.
In other men's third round matches on Thursday, Czech Tomas Berdych beat Nicolas Almagro of Spain 6-2, 6-2, and fourth-seeded Briton Andy Murray defeated American Alex Bogomolov 6-2, 7-5.
In the women's draw, fourth seed Maria Sharapova defeated Russian compatriot Svetlana Kuznetsova, 6-2, 6-3, Aussie Samantha Stosur upset Li Na of China, 6-4, 3-6, 6-4, Andrea Petkovic of Germany defeated Czech Petra Kvitova 6-3, 6-3 and second seed Vera Zvonareva routed qualifier Petra Martic, 6-2, 6-2.
Sharapova easily won the matchup of Russian former US Open champions. Kuznetsova took the title in 2004 and Sharapova won two years later.
Sharapova appears to be near the top of her game as she gears up for the US Open, which begins in less than two weeks.