PHOTOS: Djokovic imperious, Murray survives Verdasco scare

An imperious Novak Djokovic proved unstoppable as he claimed a straight-sets victory on Wednesday to set up a Wimbledon semi-final clash with Juan Martin del Potro.

Top seed Djokovic reeled off his fifth successive three-set victory although his quarter-final against Czech seventh seed Tomas Berdych was harder than the 7-6(5), 6-4, 6-3 scoreline suggested.

Untroubled so far as he targets a second Wimbledon title, the clinical Serb had to find his best tennis to subdue Berdych who beat Djokovic in their only previous grasscourt meeting.

"It was a very close match, and that's what I expected," Djokovic, who lost to Del Potro in an Olympic bronze-medal match at Wimbledon last year, told a news conference.

"Tomas is a very powerful player. We went toe-to-toe in the first set."

The 26-year-old has looked in almost total control so far and even when the dangerous Berdych began to threaten, Djokovic found an extra gear to reach his 13th consecutive grand slam semi-final.

Djokovic trailed by two breaks in the second set but quickly snapped back into action to surge to victory.

"You have to play really on the limit, playing really great to have a chance to beat him," Berdych said.

"That was not my case today."

Andy Murray put the home fans through the wringer as he came back from two sets down to book a place in the Wimbledon semi-finals with an edgy 4-6, 3-6, 6-1, 6-4, 7-5 win over unseeded Spaniard Fernando Verdasco on Wednesday.

Murray's hopes of ending Britain's 77-year wait for a men's Wimbledon champion were on the verge of being shredded as he found himself playing catch-up while looking jaded and uncomfortable on court.

The 54th-ranked Verdasco put pressure on Murray's vulnerable second serve and came up with a series of rasping winners to force the U.S. Open champion deeper behind the baseline.

Yet with the match slipping out of his grasp, Murray muscled his way back into the encounter, taking the third and fourth sets as Verdasco's level dropped and then grabbed a decisive break in the 11th game of the fifth.

He wrapped up the match after three hours and 27 minutes when Verdasco sent a forehand long.

"There's been a lot of matches where I've been behind and managed to turn it round, I don't know if it is the most emotional match, but it was an unbelievable atmosphere and great to get through," said a hugely relieved Murray, who has now reached five successive Wimbledon semi-finals.

Murray had reached the final of his last three grand slams, but he found himself under early pressure as Verdasco broke to take the first set after 45 minutes.

That was the first set Murray had dropped all tournament but the world number two shook off the disappointment to take a 3-1 lead in the second.

His tame second serve came back to haunt him, however, and he was broken in the sixth and eighth games. When Murray failed to convert any of the three break points he had in the ninth game, Verdasco surged to a two-set lead.

Faced with a mountain to climb, Murray lost the tightness that had marked the first two sets, breaking twice to take the third comfortably and then edging a close fourth as both players seemed wary of cutting loose.

Yet it was Murray who came out on top in the fifth, rifling down an ace to bring up three match points and then clenching his fist in relief when Verdasco sent a forehand long.

When his left leg jarred horribly and towering Juan Martin del Potro fell to earth after five points of his Wimbledon quarter-final against David Ferrer on Wednesday there seemed no way back.

Remarkably, a little over two hours later, with the help of some "magic" pills provided by the tournament doctor, the six foot six Argentine wrapped up a superb 6-2 6-4 7-6(5) victory to reach the semi-finals at the grasscourt slam for the first time.

Quite what sort of shape his left knee will be in when he walks on court against world number one Novak Djokovic is any one's guess - that is if he makes it that far.

"I'm not going to put my body at risks, you know," the eighth seed told reporters.

"The doctors tell me with this tape and taking some anti-inflammatories you can play.

"If they say something different, I will think."

Forced to take the initiative to avoid getting the runaround by the relentless Ferrer, who will become world No.3 on Monday, Del Potro cranked up his forehand at every opportunity.

The bandaged Del Potro broke twice to win the first set and clinched the second after Ferrer cracked under pressure at 4-4, slicing a weary-looking backhand into the net after another onslaught from the Argentine.

Ferrer seemed to lack his usual zip, possibly because of a toe injury that has been nagging him since reaching the French Open final, but he hung on grimly to force a third set tiebreak.

Del Potro sensed danger when he was 15-30 down on his serve at 4-5 but delivered a towering ace that Ferrer referred to a Hawkeye challenge more out of desperation than genuine hope.

Ferrer fell behind in the tiebreak but again dug deep to put pressure on Del Potro.

There was no escape, however, and after a long baseline rally which had the players scrurrying from side to side, Del Potro launched a forehand missile to clinch victory and this time collapsed to the turf in joy rather than pain.

"I will need to be 100 percent or 110 percent against (Djokovic)," Del Potro said of the challenge of facing the man he beat in an Olympic bronze medal match here last year.

Jerzy Janowicz overpowered compatriot Lukasz Kubot 7-5, 6-4, 6-4 at Wimbledon on Wednesday to become the first Polish man to reach a grand slam singles semi-final.

The 24th seed broke Kubot in the 11th game of a service-dominated opening set and did so again to open up a decisive 4-3 lead in the second.

The towering Janowicz, 22, had too much power for his 31-year-old opponent and he broke him again to lead 5-4 in the third set before wrapping up victory with a service winner after just over two hours.

An emotional Janowicz lay prone on the court for several seconds before the players embraced each other warmly at the net.