Grigor Dimitrov should be the favourite to lift the Wimbledon title after vanquishing defending champion Andy Murray, according to top seed Novak Djokovic.

Bulgarian Dimitrov dethroned the reigning All England Club king in a straight-sets quarter-final victory on Wednesday to set up a meeting with 2011 winner Djokovic.

World number two Djokovic edged through a five-set grind with Marin Cilic to secure his sixth semi-final at SW19.

The Serbian 27-year-old has missed just one grand slam semi-final in the last 17 - but still rates 11th seed Dimitrov as "the man to beat" at Wimbledon.

"The fact he hasn't lost a match on grass this season says it all about his quality," Djokovic said of the Queen's Club champion.

"He's definitely the man to beat here now, and winning against Andy in straight sets, many people look at him as a potential grand slam winner.

"So now that's maybe here, or maybe in the grand slams to follow.

"He has won tournaments on different surfaces this year, so he has the ability to adjust.

"His game has improved a lot, and working with Roger Rasheed as well, I'm sure that helps.

"He's getting more experienced now playing on the big stage, which is definitely useful for big tournaments like this.

"For Dimitrov to win in straight sets against Andy, he must have played an incredible match - to beat Andy on grass is a very, very difficult challenge."

"The fact he hasn't lost a match on grass this season says it all about his quality" - Novak Djokovic on Grigor Dimitrov

Dimitrov dispatched Murray 6-1 7-6 (7/4) 6-2 to stun Centre Court, but not the tennis fraternity.

Djokovic extended his 100% record over close friend Cilic with his 10th victory over the Croatian in Wednesday's last-eight battle on Court One.

The six-time grand slam winner prevailed 6-1 3-6 6-7 (4/7) 6-2 6-2, handing Boris Becker the coaches' bragging rights over Goran Ivanisevic.

Roger Federer won the battle of Switzerland against Stan Wawrinka, later admitting taking on his good friend caught him unawares in the midst of combat.

The 32-year-old remains in the hunt for that record eighth Wimbledon crown, and will take on Canada's Milos Raonic in the last four.

"I found myself thinking about that midway through the match actually," said Federer, who prevailed 3-6 7-6 (7/5) 6-4 6-4.

"I thought 'Oh, I'm playing Stan'.

"It hit me midway through the second set.

"You don't necessarily want to beat your friend, but you want to win the match, so that's the odd part."

Relieved to have recovered from last year's second-round exit to Sergiy Stakhovsky, Federer said: "There was a lot on the line and I'm really pleased to have come through.

"Last year was a major disappointment, it was very rough.

"I'm happy that one year later I'm back in the semis with a chance to go further."