Mason, Ohio : World number one Rafael Nadal battled back to defeat Frenchman Julien Benneteau 5-7, 7-6, 6-2 at the Cincinnati Masters on Thursday while Britain's Andy Murray needed a final set tiebreak to beat Latvia's Ernests Gulbis.
Third seed Roger Federer, coming off a runner-up finish in Toronto last week, enjoyed a free pass into the quarter-finals after his opponent pulled out of their match with an injury.
The top-ranked American, Andy Roddick, produced one of his better performances in some time to overcome Swedish fifth-seed Robin Soderling.
Nadal, who struggled to find his rhythm against a confident Benneteau, lost the first set and was then forced to save match point in the second.
With his French opponent struggling physically in the final set, Nadal showed his excellent fitness and cruised to victory and booked his spot in the quarter-finals.
Next up for Nadal is Cypriot Marcos Baghdatis who pulled off an impressive victory over Czech Tomas Berdych.
Murray also looked far from his best in the opening set against an occasionally inspired but often erratic Gulbis.
But Murray fought back in the second with the Latvian missing out on break point in the third game and hurling his racket to the ground three times before it was disfigured.
Gulbis had another good chance to gain control of the match when he had break point in the eighth game of the third set but skied a shot high into the air and Murray held to make it 4-4.
Results
9-Andy Roddick (US) beat 5-Robin Soederling (Sweden) 6-4 6-7(7) 7-6(5)
6-Nikolay Davydenko (Russia) beat 10-David Ferrer (Spain) 4-6 6-3 7-5
1-Rafael Nadal (Spain) beat Julien Benneteau (France) 5-7 7-6(6) 6-2
Marcos Baghdatis (Cyprus) beat 7-Tomas Berdych (Czech Republic) 7-5 6-4
3-Roger Federer (Switzerland) beat Philipp Kohlschreiber (Germany) walk over
2-Novak Djokovic (Serbia) beat David Nalbandian (Argentina) 6-1 7-6(7)
4-Andy Murray (Britain) beat Ernests Gulbis (Latvia) 4-6 6-3 7-6(4)
Mardy Fish (US) beat Richard Gasquet (France) 7-5 6-2
