Djokovic and Del Potro reach semi-finals

Andy Murray had to scrap his way through a five-set thriller but Novak Djokovic encountered little trouble in reaching the Wimbledon semi-finals as he destroyed the hopes of Tomas Berdych.

Having seen Rafael Nadal and Roger Federer exit the tournament last week, the Wimbledon crowd looked set to witness yet another shock when Fernando Verdasco raced two sets up against second seed Murray.

Willed on by fellow Scot Sir Alex Ferguson, Murray produced a heroic comeback to record a 4-6 3-6 6-1 6-4 7-5 win on Centre Court.

There were no such problems for Djokovic, who beat seventh seed Berdych 7-6 (7/5) 6-4 6-3 over on Court One.

The Serbian had a figure familiar to Ferguson in attendance, with Manchester United captain Nemanja Vidic taking a place among the crowd to cheer on his compatriot.

Djokovic came off second best at times against his hard-hitting opponent, but the world number one is feeling good about his chances of winning Wimbledon for a second time after coming through his first five matches without dropping a set.

"Coming into the semi-finals I feel physically fresh, I'm ready and I have plenty of motivation to win every match that I play," said Djokovic, who plays Juan Martin Del Potro in Friday's semi-finals.

"Tactically I will make a few adjustments and analyse my opponent.

"He's kind of a similar opponent to the one that I had today.

"He is tall, has a powerful serve and has quite flat shots from both sides on the baseline and he can move around the court quite well for his size."

There are question marks over Del Potro's fitness even though he came out on top in the battle of the walking wounded against David Ferrer .

Ferrer had to cut short his pre-match practice session on Court 16 after struggling with an injury, but it was Del Potro who seemed the more likely to have to pull out.

After falling and damaging the knee in the final stages of his third-round win over Slovenian Grega Zemlja, eighth seed Del Potro went over in an almost identical fashion today, inside the first game, as he chased down a ball to his left.

He lay on the ground, wincing in pain and clutching the knee before help arrived, first in the form of the trainer and then with the tournament doctor.

Somehow Del Potro recovered to pull off a 6-2 6-4 7-6 (7/5) victory, but he may have to hand Djokovic a place in the final if doctors advise him against stepping out on court for the semi-finals.

"I'm not going to put my body at risk," Del Potro said.

"The doctors tell me that with this tape and some anti-inflammatories I can play. If they say something different, I will think.

"I think I was close to retiring. But to be honest, I didn't want to retire in my first quarter at Wimbledon against David Ferrer. The doctors gave me good anti-inflammatories.

"I was thinking good things, being positive all the time. I never thought about my knee after the first set."

Murray, meanwhile, will play Jerzy Janowicz on Friday after the 6ft 8in ace specialist came out on top in the battle of the Poles, defeating Lukasz Kubot 7-5 6-4 6-4.

"Right now I'm the most happy person in the world," said the world number 22, whose previous best performance came last year when he reached the final of the Paris Masters.

"I was in the final at Paris Bercy. This is a little bit of a different situation. You have different kind of emotions in your heart, so I think this Wimbledon goes in front of Bercy."