Roger Federer reached a ninth Wimbledon semi-final after beating his great friend Stan Wawrinka in an all-Swiss battle on Centre Court.

The seven-time champion has never lost at the last-four stage at the All England Club and gave himself the chance to reach another final after taking national bragging rights with a 3-6 7-6 (7/5) 6-4 6-4 victory.

With Rafael Nadal and Andy Murray already out, there was a point on Wednesday afternoon when both Federer and Novak Djokovic - the other members of the 'big four' - were in danger of tumbling out too.

Djokovic dug himself out of a deep hole to see off Marin Cilic, though, and Federer seized charge against Wawrinka once he levelled the contest in their second-set tie-break

Wawrinka, who had been struggling physically, displayed his tenacity at the end to save four match points.

But on the fifth Federer followed up a scorching serve, that Wawrinka did well to float back, with a lethal smash from mid-court.

Federer had been surprised to learn of Grigor Dimitrov's success against Murray.

"It's always a shock when the defending champion goes out and it puts even more pressure on the favourites," he said.

Given his vast experience, many will now fancy Federer to go on and land a record eighth title, despite the competition that remains.

Wawrinka, who at 29 is three years Federer's junior, won the Australian Open at the start of the year and pushed his more illustrious countryman hard throughout.

Federer acknowledged that, saying on BBC2: "Stan played great, especially for the first two sets.

"After that he started to struggle maybe a little bit with his fitness."

Wawrinka called for the doctor at one point, although it was not immediately obvious what was troubling him.

"Maybe he was struggling early on but he was hitting the ball too well, too cleanly, for me to do anything on it," Federer said. "So I had to wait over two-and-a-half sets to get my first break against him.

"I'm very pleased with the match. We both played at a high level and I wish Stan all the best for the rest of the season because he's already had a beauty."

Federer is reluctant to think of another Sunday showpiece match at this stage, but knows he has a great semi-final record at Wimbledon.

"No doubt, but then again I don't want to get too far ahead of myself," he said.

"I'm just really pleased I'm back strong at Wimbledon. Last year was such a disappointment because it's always one of the highlights of the season for myself, to play well at Wimbledon and try to win it."

Ukrainian Sergiy Stakhovsky halted Federer in the second round 12 months ago, as the Swiss master failed to reach a grand slam quarter-final for the first time since 2004.

"Last year I didn't even come close so I was very deflated leaving Wimbledon on that note," Federer said.

"It's good to be back in the semis and having the chance to go a step or two further. The prospect is very exciting."