By Pritha Sarkar

LONDON (Reuters) - When self-styled "old guy" Roger Federer clocked that he was on a semi-final collision course with an all-conquering world number one, his vision of holding aloft the Wimbledon trophy for a record eighth time may have seemed like a pipe dream.

However, the shock demise of top seed Novak Djokovic at the weekend not only elevated the Swiss to a position as the man to beat, it also raised the possibility this could be the week when he finally ends his four-year hunt for an 18th grand slam title.

Federer's previous strategy would have been to focus all his energy on upending the only man who has wrecked his grand slam hopes over the past year.

However, he can now dare to imagine hoisting the pineapple-topped trophy again -- as he has a winning head-to-head record against every man left in the draw, including his potential final opponent Andy Murray.

As Federer begins his countdown to a possible 11th appearance in the final, his first task will be to topple Croatian beanpole Marin Cilic in Wednesday's quarter-final.

Federer recalled that the ninth seed "blew me away" the last time they met -- in the semi-finals of the 2014 U.S. Open which Cilic went on to win -- but this time round he was ready for anything the Croatian could throw at him.

"I know what I'm getting into," said Federer, who owns a 5-1 record in meetings with Cilic.

"He's really tough to play. He's really improved his serve in the last few years, especially since the U.S. Open. He can clearly do it here at Wimbledon, too.

"But I'm happy about my game as well. I'm confident going into the Cilic match," added the man who was runner-up to Djokovic in the last two Wimbledon finals.

A lot of that belief comes in the knowledge that should he navigate his way past Cilic, waiting for him in the semi-finals will be either Djokovic's conqueror, American 28th seed Sam Querrey, or Canadian Milos Raonic.

SAMPRAS INSPIRATION

Whereas a week ago Federer was "not thinking of the title" -- with doubts remaining about his fitness after he sat out the French Open with a bad back -- chances are that after Djokovic lost on Saturday, the 34-year-old has thought of little else.

While many pundits and fans alike are tipping Murray as the man who will now go on to lift the gilded Challenge Cup on Sunday, Federer could do worse than draw inspiration from another seven-times Wimbledon champion.

Fourteen years ago American Pete Sampras was written off as a 'has been' after he lost in the French Open first round and was then jettisoned out of Wimbledon in the second round -- by 145th-ranked journeyman George Bastl.

By the time he arrived at the U.S. Open in August, his ranking had tumbled to 17th in the world.

Even when he beat Greg Rusedski to reach the fourth round, the Briton bluntly declared: "I'd be surprised if he wins his next match. I think the movement is not the same and the fitness is not the same.

"He's just not the same player from the past."

Sampras responded to the churlish outburst in the only way a true champion knows how -- by winning the title.

With similar words being whispered about Federer last week -- after he arrived at Wimbledon without winning a title in the first six months of the year for the first time since 2000 -- the world number three also let his racket do the talking.

After four matches, his record stands at 12 sets contested, 12 sets won.

"Right now I enjoy everything about Wimbledon," said Federer, whose absence from Roland Garros ended a run of appearing in 65 consecutive slams.

"Clearly I missed being in Paris... but that decision was for Wimbledon, it was for the rest of the season, it was for the rest of my career.

"I love this tournament more than anything. It's a huge opportunity for me to turn around the season. 

"In tennis, there's not that much more (goals left to achieve). I hope I can win Wimbledon one more time. That would be nice."

(Reporting by Pritha Sarkar, editing by)