Nadal struggles, Federer walks through as top four advance

The top-seeded Spaniard saved a match point in the second set to stay alive as hot conditions began to tell on his 32nd-ranked opponent from Geneva, who lost the last time they played five years ago.

Holder Roger Federer received another huge break as he advanced by walkover as third-round opponent Philipp Kohlschreiber retired before their match with a right shoulder injury.

Federer, who received a bye in the first round, has yet to play a complete match this week. He won his first contest Wednesday night when Denis Istomin suffered an ankle injury in their first set and had to retire after 32 minutes.

Second seed Novak Djokovic, finalist at the last two editions with losses to Andy Murray and Federer, produced the only straightforward victory of the day as Argentine David Nalbandian continued to cool after his 11-match win streak ended last week.
The Serb reached the last eight 6-1, 7-6 (9-7).

"I was really happy with today's performance. Considering the conditions, which are very fast here as well, it was not easy to stay in the point with David," Djokovic said. "But I did and managed to play well when I needed to in second set to go through."

Toronto winner and fourth seed Murray said he felt the heat draining away his energy but held on to put out Latvian Ernest Gulbis 4-6, 6-3, 7-6 (7-4).

"I've played seven matches in nine days, every one of them between 12 and 3 p.m.," the Scot said. "Everybody would be feeling like that in my position.

"You spend a lot of time after the matches making sure you recover as best as possible and just hope the next day you feel good."

Murray had a much-disliked ice bath after his previous win. He added optimistically: "Tomorrow it could be nice and cold. We don't know, so have to wait and see."
Murray, winner of seven straight matches, will have to pull up fit Friday when he faces on-form Mardy Fish.

The Floridian, back-to-back winner of Newport and Atlanta titles last month, booked his place in the last eight with minimal effort as he defeated Frenchman Richard Gasquet 7-5, 6-2 in little more than an hour.

Murray needed four match points to get past Gulbis after winning their first four matches and losing only one set from 11 played.

Murray has lost twice this season to Fish, who attributes a 20-kg weight loss last autumn with his revitalized form. He took out Murray in Miami and at Queen's club, London.