ANDY Murray is through to his sixth Wimbledon semi-final in the last seven years after beating Vasek Pospisil 6-4, 7-5, 6-4 on Centre Court.

A match interrupted by two rain delays, and finished under the closed roof, it was the third seed's 150th career victory in a Grand Slam tournament. His opponent in the last four on Friday will be Roger Federer, who beat Gilles Simon 6-3, 7-5, 6-2 on No 1 Court.

"I felt like I played some good stuff," Murray said after his victory. "I hope I can get to another final, but it's going to be a tough one. Hopefully we can have a great match - we've played some good ones here in the past."

It did not long for Murray to seize the initiative against his Canadian opponent, whom he broke in the third game. After the Scot served to go 3-1 up, the rain began to fall and the covers came on for the first time.

When play resumed nearly 40 minutes later - still with the roof open - Murray's serve was a little vulnerable at first. Once the home favourite got up to speed, however, there was nothing the world No 56 could do to prevent him taking the first set.

The bulk of the second set was closer, and when the rain returned to force a second delay it was on serve at 4-3 to the Canadian. Such interruptions often favour the lesser player, but when the match started up again, this time under the closed roof, there was nothing he could do to threaten Murray's serve.

At 5-5, Murray decided to attack the Pospisil serve, and he was rewarded for his effort with a break. At 30-30 Pospisil, who had been taking his time between points, was given a warning for time-wasting from the umpire, and two points later he was broken by some excellent returning.

Murray double-faulted once when serving for the second set - an indication, perhaps, that all was not entirely well with the shoulder that had needed treatment during his third-round match against Andreas Seppi. But, such lapses apart, his serve was functioning well and his return was close to its best. At the same time, Pospisil was committing far too many unforced errors, with it being noticeable during quite a few rallies that Murray would keep them alive for shot after shot as he waited for his opponent to err.

The third set followed a similar pattern to the second, with Pospisil holding serve to maintain a foothold in the contest. Of the Canadian's four previous victories, three had been in five sets, including a comeback from two sets to love down in the previous round against Viktor Troicki. Murray therefore knew that his opponent could not be written off lightly, even though there were signs of tiredness from Pospisil, who had been on court in his singles matches for three hours more and had also been involved in the men's doubles.

Pospisil saved a couple of break points in the seventh game to go 4-3 up, then in the following game received another code violation for time-wasting - this time forfeiting a first serve. He was 0-30 down at the time, and although he got back to 30-30, a bad miss got him into trouble and Murray grabbed the chance to convert the break point.

Serving for the match, Murray played a couple of uncharacteristically sloppy points that allowed Pospisil his first break point of the contest. But he recovered from that blip to take the game on his second match point. Nearly three and a half hours had elapsed since the match began, although the actual playing time was just under two and a quarter hours.