Rafael Nadal, Andy Murray needs 3 sets, close tiebreakers to avoid upsets in Cincinnati

to avoid a huge upset. And he wasn't alone in the midday distress.

Nadal and No. 4 Andy Murray were pushed to their limits Thursday before moving on to the quarterfinals of the Cincinnati Masters. Both got some help with their matches on the line.

Nadal survived a set point in the second-set tiebreaker, then surged to a 5-7, 7-6 (6), 6-2 victory over France's Julien Benneteau, who developed leg cramps in the final set and wasn't the same. A worn-out Murray took advantage of Ernests Gulbis' erratic shots — especially in the tiebreaker — for a 6-4, 3-6, 7-6 (4) victory.

"The heat here is important," Nadal said. "It's not easy to play here."

Andy Roddick couldn't blame the heat for his full-length match. The top-ranked American played in the evening and wasted five match points — one of them during a second-set tiebreaker — before closing out a 6-4, 6-7 (7), 7-6 (5) win over No. 5 Robin Soderling.

"What's the difference between winning by two points in a tiebreaker and losing by two points?" the Roddick said. "A little bit of good play and luck also."

The other top players had an easier time.

No one has played less this week than second-ranked Roger Federer, who reached the quarterfinals when Germany's Philipp Kohlschreiber withdrew because of a painful right shoulder. It was the second straight match that Federer's opponent got hurt. He's been on court for a total of 28 minutes this week.

Third-ranked Novak Djokovic advanced by beating David Nalbandian 6-1, 7-6 (7).

Stunningly, Nadal came within one point of an early elimination. Benneteau served consecutive aces to go up 6-5 in the second-set tiebreaker, but hit a return long. Nadal then ran around a shot and nailed a forehand into the corner, grabbing the momentum. He jumped and punched at the air when Benneteau hit a shot wide to end it.

"He had two aces and after that, I played very good," Nadal said. "My game was on and off. My forehand worked very well — for moments."

During the break, Nadal got a blister pad applied to the bottom of his right foot. Benneteau got his legs rubbed for cramping. Nadal was much better off, breaking Benneteau twice to pull ahead 3-0 in the final set. Nadal pumped his fist at the end of the 2-hour, 48-minute match.

Murray was exhausted after his comeback, moving on with more stagger than swagger.

The 23-year-old Scot won his second straight Rogers Cup championship in Toronto on Sunday, beating Federer to defend his title. Fatigue has caught up with him in Cincinnati.

Murray wore down during his match against the 21-year-old Gulbis, who was the youngest player left in the field. He repeatedly bent over and tried to catch his breath after long rallies in the 85-degree heat.

"The conditions are tough here," Murray said. "I've played seven matches in nine days, and every one was between noon and 3 o'clock, when it's warmest. I think anybody would be feeling (tired) in my position."

Murray got his serve broken to open the match and was soon talking to himself and swatting balls away in frustration. He evened the match after two sets by taking advantage of the Latvian's frequent mistakes — 42 unforced errors overall.

Gulbis' worst moments came in the third-set tiebreaker. He hit a backhand into the net, sailed a forehand, then plopped a forehand into the net, giving Murray a 3-0 lead. When Gulbis sailed another forehand, Murray was up 6-1 and in position to close out the 2-hour, 33-minute match.

Murray asked to play a night match in the quarterfinals on Friday, giving him a break from the heat and more time to recover. The doubles scheduled prevented it, so Murray will play in the afternoon again.

The 13th-ranked Roddick had 12 break points — five of them during one game of the third set — but converted only two of them. He blew three match points in the final game of the third set, sending it to a tiebreaker that ended with Soderling's long forehand.

Match time: 2 hours, 44 minutes.

Roddick missed Toronto last week because he's getting over a mild case of mononucleosis. He has already surpassed his expectations in Cincinnati.

"I think each match is getting a little better," he said. "To put three good matches together here was extremely necessary going into the U.S. Open."

Federer has had the easiest time this week. He played only 28 minutes in his opening match before qualifier Denis Istomin had to quit because of an injured right foot on Wednesday night. Federer didn't even leave the locker room on Thursday — Kohlschreiber's shoulder hurt so bad during a morning practice that he scheduled an MRI.