Grigor Dimitrov is now the favourite to lift the Wimbledon title, according to top seed Novak Djokovic.

Bulgarian Dimitrov unseated defending champion Andy Murray with a straight-sets quarter-final victory, to set up an All England Club semi-final against Djokovic.

Serbian world number two Djokovic edged through a five-set battle with Marin Cilic to reach the last four and his sixth semi-final at SW19.

Djokovic has missed just one grand slam semi-final in the last 17 - but still rates 23-year-old 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 Queen's Club champion Dimitrov.

"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."

Djokovic extended his 100 per cent 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.

Cilic fended off a nerve-wracked start to push the match into five sets, with Djokovic often frustrated with own shortcomings.

The French Open finalist admitted he wrestled with his composure, finally able to regain control to complete victory.

"You will always go through difficult moments, especially two sets to one down in the quarter-final of a grand slam," the 2011 Wimbledon winner said.

"It gets very emotional, you're fighting on the court as much as your opponent and you just try to mentally stay strong and find that inner strength that can help you in those moments.

"That's what helped me: you draw on experience. I've been there and played plenty of five-setters in my life.

"I was down and coming back so I knew what I needed to do.

"Marin is experienced nevertheless but I thought he got a little bit tired physically.

"I felt I did pretty well in the last two sets."

Cilic lamented his missed opportunity, before tipping Djokovic and Federer to progress to the final.

"I would say that's a chance missed," Cilic said after his first Wimbledon quarter-final.

"What was sad for me was the beginning of the fourth set - I gave him the opportunity to come back into the match.

"From that moment I knew I had to fight to work back into the match, but I didn't have any chances unfortunately.

"Overall I am very pleased with my 10 days, though, and I feel I have improved through it.

"I would say Novak is the slight favourite for his semi-final, even though Dimitrov is in great form.

"Roger has to be the favourite from the other half of the draw, for sure."