Andy Roddick admits his epic Wimbledon "dogfight" with Lleyton Hewitt has taken its toll on him mentally.

It was the 12th meeting between the players but arguably their best contest yet, with five sets and almost four hours of tennis needed to separate them on Court One.

Roddick eventually emerged a 6-3 6-7 (10/12) 7-6 (7/1) 4-6 6-4 winner to set up a semi-final clash with home favourite Andy Murray, and the sixth seed was relieved to survive.

"It certainly wasn't short on drama," Roddick said. "It was tough from a mental standpoint, because Lleyton wasn't going away and there were kind of a lot of ebbs and flows to the match.

"I'm just happy to be on the good side of it. Right now it's a mixture of happiness, of relief. In your mind you're trying to stay the course for four hours, constantly figuring out what you're going to do.

"Your mind is just racing for four hours, so then it's relief, happiness, and almost an instant shutdown mode. But I was happy to be through."

Having eased past Tomas Berdych in his last match, Roddick was pushed to the limit by Hewitt, who refused to give up despite seemingly struggling with a leg injury in the final two sets.

And the 26-year-old, who has twice finished runner-up at Wimbledon, conceded the last set was a struggle.

"Recovering from the fourth set was hard," Roddick said. "I thought he started playing a lot better there.

"And the fifth was a dogfight too. I had to come up with probably the best half-volley I've ever hit in my life to save break point.

"But I played a lot better in the fifth than I did probably from the second on. I returned a lot better and even had looks early in the set, but he came up with some good serves.

"There were a lot of tough parts during that match."

Hewitt was left to rue two errors at the end of the deciding set which cost him a break in game nine and ultimately the match.

"I couldn't take my chances when I needed to," said Hewitt, the 2002 champion.

"I just missed a couple of short forehands there when I had the opportunity to come in on his backhand.

"Then on break point I actually played a good point, and he came up with a good pass. He hit a lob at my feet. I had to come up with a half-volley, but wasn't able to hit the half-volley short enough. So he got up there and hit a good pass."

Despite the defeat, Hewitt's surprise run to the last eight has renewed the 28-year-old's self-confidence, especially after wins over seeds Juan Martin Del Potro and Radek Stepanek along the way.

"Coming into this particular tournament I felt pretty good physically, and I knew mentally I'd be able to hang around for five sets against the best guys," Hewitt explained.

"It's more just an extra added belief now that I can go out there and can do it more than anything.

"There's a lot of positives to take out of it. The guys that I've beaten, especially the Del Potro match, the way that I actually went out there and took it to him.

"Even losing to Andy today, he's one of the best grass-court players out there. He's been to a couple of Wimbledon finals, a few semis here as well.

"I would have liked to have snuck through but it's not a bad loss."