LONDON: Kevin Anderson produced an astonishing fightback from two sets down to beat eight-time champion Roger Federer 2-6 6-7(5) 7-5 6-4 13-11 in a quarter-final cliffhanger at Wimbledon on Wednesday.

The big South African's hopes looked forlorn as Federer skipped through the opening two sets on Court One with his usual panache but he turned the match on its head to cause the biggest shock yet in a tournament full of upsets.

It was his first win against Federer at the fifth attempt and means he is the first player representing South Africa to reach the semi-final here since Kevin Curren in 1983.

Eighth-seed Anderson, 32, saved a match point in the 10th game of the third set and grew in confidence against an increasingly-ragged Federer who had won the first set in 26 minutes.

He won the third set to snap Federer's 34-set winning streak at Wimbledon and Federer was clearly shaken as Anderson dominated the fourth set to drag the 20-times Grand Slam champion into a decider.

Six times Anderson was required to hold serve to stay alive and each time he was equal to the task.

Federer eventually cracked at 11-11, double-faulting to hand Anderson a break point which he converted when the defending champion hit a weary-looking forehand halfway up the net.

Anderson stayed cool and sealed victory on his first match point with a powerful first serve which Federer could only return into the tramlines.