Wimbledon 2014: Roger Federer remains on course for eighth title after victory over compatriot Stan Wawrinka

The seven-time champion beat his fellow Swiss 3-6, 7-6, 6-4, 6-4 to reach the semi-finals

Roger Federer celebrates winning his men's singles quarter-final match against Stanislas Wawrinka (GETTY IMAGES)

Roger Federer's quest for a record-breaking eighth Wimbledon title continues apace after victory in the Swiss derby on Centre Court, where Basle defeated Lausanne 3-6, 7-6, 6-4, 6-4. Friday's semi-final will be Federer's third match in four days, but playing for the third time on successive days caught up with his compatriot Stan Wawrinka, who had complained in vain about the scheduling after his third round match was held over from Saturday to Monday because of rain.

Seeking medical assistance after losing the second set, he never looked himself again and was playing from memory by the time he managed to save four match points but not a fifth.

Davis Cup team-mates and Olympic gold medallists together they may be, but until losing energy, Wawrinka was in no mood to defer to the older man, whom he overtook as Swiss No 1 after winning the Australian Open in January. Having beaten Federer in their most recent meeting in Monte Carlo this year encouraged his self-belief too, even if it left him 13-2 behind on head-to-heads.

That was carried into the first set, won in only half an hour and it was just one mistake that cost him the second in the tiebreak. At that stage Wawrinka called for assistance and took some pills for an unspecified ailment after which he began to look a little more sluggish. By the time they took effect the third set had gone and the fourth also required only one decisive break of serve.

“Stan played great, especially in the first two sets, then started to struggle,” Federer said. “He was hitting the ball too cleanly for me to do anything with it. I don't want to get too far ahead of myself but it's good to be back in the semi-final.” He has played eight at Wimbledon and not lost one yet.

If the Federer backhand is a thing of beauty, Wawrinka's, also single-handed, is a bludgeon that he employed to powerful effect. If anything was going to let Wawrinka down it was a first serve that hit the spot barely 50 per cent of the time. Considering that, Federer was able to force few break points for a long time. In the first set he was allowed only one, failing to take it after having fallen behind to a break in only the fourth game. A smash from Wawrinka after Federer tried to lob him brought three set points, the second of which was gleefully accepted.

It meant Federer had dropped a set for the first time here this year and he was in no mood to do so again. Serving first this time, the former champion was able to hold comfortably and theoretically keep the pressure on, although without coming close more than once to a break.

So a tiebreak it was, in which one crucial mistake by Wawrinka, sending a forehand too long, allowed his opponent to serve and volley for 7-5 and equality.

In the third set Wawrinka's service games became more erratic and after saving two break points at 1-1, he failed to do so at 3-3. For the first time in the match the senior man was on top and again the shot to seal the set was an emphatic one, smashed from overhead.

Federer, merciless, kept him running from side to side, up and back and made the break early for a 2-1 lead, quickly extended and eventually consolidated to earn yet another Grand Slam semi-final. It will be his 35th, easily a record, and only Jimmy Connors has won more matches here (84-72).

He will be favourite to be walking out for Sunday's final against either Novak Djokovic or Grigor Dimitrov, which would enable him to reclaim his position as Swiss No 1 and put Wawrinka in his place for the second time in a week.