Andy Murray wins to advance to the last eight in Cincinnati

Murray served 11 aces and hit 21 winners in a timely return to form

Britain's Andy Murray booked his place in the quarter-finals of the Western & Southern Open with a straight sets win over American Alex Bogomolov Jr.

The Scot imposed himself early on to take the first set and, after a second-set wobble, he finished strongly.

Murray won 6-2 7-5 in an hour and 41 minutes and will next play Gilles Simon after he overcame David Ferrer.

Rafael Nadal battled past Fernando Verdasco 7-6 (7-5) 6-7 (4-7) 7-6 (11-9) and Novak Djokovic beat Radek Stepanek.

Third seed Roger Federer took just 55 minutes to defeat American James Blake 6-4 6-1 in the night match, while in the women's draw there were wins for second seed Vera Zvonareva and fourth seed Maria Sharapova.

Bogomolov caused a major upset when he beat Murray in Miami in March, but a repeat performance seemed unlikely as the Briton saved two break points in game four to secure a 4-0 lead.

A lapse in concentration saw Murray's serve broken late in the first set but Bogomolov had no answer to the world number four's powerful forehand winners, as Murray took the opener.

Bogomolov, who beat 15th seed Jo-Wilfried Tsonga in round two, showed glimpses of his best form in the second set but gifted Murray a 2-1 lead after an ill-timed double fault.

Russian-born Bogomolov broke back to make the score 5-5, with the Scot unable to hide his frustration after a string of unforced errors.

But Murray broke again to set up the chance to serve for the match - and avoid the possibility of a third set in the soaring Midwest heat.

It was an opportunity that Murray took with an ace, his 11th of the match, to advance to the last eight of a tournament he won in 2008.

"I played better today," said the Scot. "I was struggling a lot in Miami and didn't play well at all. So I am glad to come through in two sets and forget about the match I played against him in Miami."

Murray wil play 10th seed Simon, who beat fifth seed David Ferrer 6-4 6-7 (3-7) 6-4, at 1600 BST on Friday.

Nadal endured a far less comfortable passage in his three-hour-and-38-minute encounter with fellow Spaniard Verdasco.

The world number two came from a break down in the final set and let a 5-1 lead slip in the decisive, error-strewn tie-break, squandering three match points - and four in total - before finishing off his compatriot.

It was a match that lacked the expected quality as Nadal made 41 unforced errors and Verdasco 59.

"The truth is that I am very happy," said Nadal. "Very content with the victory. It was a tough match for both of us."

Nadal goes on to face Mardy Fish after the American beat France's Richard Gasquet 7-5 7-5.

Tomas Berdych of the Czech Republic eased to a 6-2 6-2 win against Spain's Nicolas Almagro and will next meet either Roger Federer or Juan Martin del Potro.

In the women's draw, without the beaten Caroline Wozniacki and the absent Williams sisters and Victoria Azarenka, Sharapova remained on track with an impressive 6-2 6-3 win over 14th seed Svetlana Kuznetsova.

"I felt really good considering I was playing a pretty tough opponent," said Sharapova. "We've had really tough matches in the past, usually three setters. So it was quite nice to get that win in two.

"She's someone who has a tremendous amount of experience and is a really solid player, always dangerous."

Zvonareva beat Petra Martic 6-2 6-2, but fifth seed Li Na, sixth seed Petra Kvitova and eighth seed Marion Bartoli all failed to make the last eight.