Dubai: World number four Andy Murray wasted six match points and overcame a knee injury to beat Tomas Berdych 6-3 7-5 in the Dubai Tennis Championships quarter-finals on Thursday.

"I had a problem with it (the knee) since Brisbane and it's come and gone," Murray said after a match played in searing desert heat.

"It was a bit sore right before the tournament. I didn't feel it at all in the first couple of matches, and then right at the beginning of the second set I felt it.

"It's not something that stops me sort of running around. I want to try and get rid of it, because there are a lot of the big events coming up."

Seven of the world's top 10 players made the Dubai quarter-finals and Murray went into his match hoping to improve on a 3-1 losing record against the 26-year-old Czech Berdych.

Murray appeared to be cruising at one set up and 2-0 ahead in the second, but he double-faulted to gift Berdych a break back for 2-2.

Murray's movement was increasingly laboured but his reply was immediate, breaking again, only for Berdych to do the same and level at 3-3.

The Czech was on top and looked as though he could square the match, but Murray dug in and broke once more, playing a forehand cross-court shot from wide of the tramlines that Berdych had no reply to for a 6-5 lead.

Murray, 24, wasted six match points on serve. The first three were backhands into the net and a fourth an errant forehand drive but he eventually triumphed when Berdych put a forehand long.

"In my whole career on the tour, I think I've only lost one match where I served for it, two maximum," said Murray.

"I played three great serves to bring it to 40-love and then missed a few first serves in a row and he went for some big shots," he added.

"Once you're back at deuce you're thinking, God, I've just blown three match points. So you kind of just want to try get through it if you can. I went too defensive. I went too far behind the baseline and was letting him dictate points.

"I thought tactically I did well for a set and a half."

Murray's solitary defeat in 2012 came in a five-set epic against Novak Djokovic in the Australian Open semi-finals and he will meet the Serb in the last-four in Dubai should the world number one overcome compatriot Janko Tipsarevic later on Thursday.