London - Roger Federer motored into his 21st consecutive Grand Slam semi-final as the second seed moved closer to more tennis history with his 6-3, 7-5, 7-6 (7-3) defeat of Ivo Karlovic Wednesday at Wimbledon.

Federer put forth an efficient effort in taming the towering Croatian in one hour, 42 minutes, with the Swiss now awaiting his last-four opponent as Tommy Haas faced fourth seed Novak Djokovic.

Federer is now two victories away from setting the all-time mark for the most Grand Slam singles titles, 15, one more than himself and Pete Sampras currently hold. He levelled with the American by winning his first French Open last month.

The Swiss broke the fearsome Karlovic serve twice in their contest, which runs his record against the towering Croatian to 9-1.

After taking the first two sets with a break apiece, Federer produced four love games in the third under bright sunshine to set up a tiebreaker.

He earned a margin of four match points, with Karlovic raining down a 23rd ace to save the first, only to be caught by a silky forehand winner from Federer, who has now won his last 17 matches.

"It's difficult to play Karlovic, there are no rallies with him," said Federer, who reached his seventh consecutive semi-final at the All England club with 39 winners.

"There are no baseline rallies with him or with my serve either. Mentally it's tough to break him, so I'm happy I did it twice to win the match.

"I'm playing very consistently and injury-free," said the father- to-be whose wife Mirka was in the stands perhaps a month from her due date.

"I've played well this week and I'm moving into a position to win the event again," added the five-time champion who was beaten in the 2008 final by Rafael Nadal.

"I really couldn't be more confident with my game, I'm coming in on a win streak. Maybe I'd be more confident if I'd won last year, but I have a great feeling on the court. Whatever comes in the semi-finals will be difficult." (dpa)