Federer was bounced out in the quarterfinals in five sets. (AP)

Before Wednesday, Kevin Anderson had not won a set off of Roger Federer in four tries. It looked like it would be five when Federer had a match point in the third set, while leading by two sets to none.

Instead, it's the South African who is into his first Wimbledon semifinal after a 2-6, 6-7 (5), 7-5, 6-4, 13-11 marathon win. 

"I kept telling myself that today was going to be my day," the 32-year-old said after the biggest win of his career. 

Federer had never lost a match at Wimbledon after holding match point, though he was well off the mark during his only chance against Anderson:

About that moment Federer said, "At that point I wasn't thinking of losing."

As expected, the Twitter-sphere was stunned by the result, perhaps more stunned than the players themselves. 

At least Britain's Liam Broady found the light in the situation:

Of course, the Federer loss really opens up the chances for the remaining players in the draw, which includes Novak Djokovic, Rafael Nadal, John Isner and Anderson. 

It marks Federer's first loss before the semifinals at Wimbledon since 2013 and snaps his 34-set win streak at the All England Club. It's just the third time he's lost a major match after being up two sets to none. The 37-year-old vows to be back.

"Yeah, of course, the goal is to come back here next year," he said. "I wouldn't call it 'unfinished business'. I felt like I did some good business here in the past already. So I'm all right. Just disappointed now."

Strokes of Genius is a world-class documentary capturing the historic 13-year rivalry between tennis icons Roger Federer and Rafael Nadal. It is timed for release as the anticipation crests with Roger as returning champion, 10 years after their famed 2008 Wimbledon championship – an epic match so close and so reflective of their competitive balance that, in the end, the true winner was the sport itself.