It was the second time Federer dropped a two-set lead at Wimbledon - after a reverse to Jo-Wilfried Tsonga in 2011 - and the fifth time he lost at a major when holding a match point.
"I had moments where I was great, I felt like I was reading his serve". Now I feel horribly tired and just terrible. I don't know if it had something to do with the breeze, just a bad day from my side, except the first set. In all, the two battled it out for over four hours.
All told, this match is a true tossup and it wouldn't be a surprise if it extends deep into the fifth set before a victor emerges.
It was a surprise result that now sends the eighth-seeded Anderson to the semifinals at Wimbledon, his first time making it that far in the storied competition that Federer has won eight times, including previous year.
Ho-hum. It's another Wimbledon quarterfinal appearance for Roger Federer, who seeks a fifth straight and 13th overall trip to the semifinals at the All-England Club when he takes on No. 8 seed Kevin Anderson on Wednesday in London.
But this time Federer cracked, serving his first double fault at 11-11 to give Anderson the crucial break that ushered the Swiss legend to the exit door.
"I've been there before".
"Facing off that match point, then getting a break the next minute, I'm like, I've got the third set in the bag". I was able to bring that.
Federer, whose form here made it look increasingly likely he would become the first man in the professional era to win five Grand Slam titles after the age of 30, said fatigue had not been a factor even when the match went into its fifth hour. I wasn't horribly negative the whole game. This is Djokovic's second consecutive Wimbledon quarterfinal.
Novak Djokovic defeats Edmund at Wimbledon
Alexander Zverev suffered a third-round exit at Wimbledon , losing to the Latvian Ernests Gulbis. "My elbow was bothering me". The Japanese player has already lost twice to the former world number one this year - on clay in Madrid and Rome.
The 20-time Grand Slam champion, who turns 37 next month, says he plans to return to SW19 next year.
"It motivates me to do extremely well here because I don't want to sit here and explain my loss. Beating Roger Federer here at Wimbledon will be one I remember, especially in such a close match", Anderson said.
"You are reluctant to write Roger off - just the way that he moves around the court and he stays injury free", said the Australian, who won the title in 1987.
"I couldn't come up with enough good stuff for him to miss more".
There's a sense of loss whenever Federer is beaten because he's so good to watch.
When Wimbledon got underway July 2, tennis fans of all loyalties seemed united in rooting for one pairing in Sunday's men's final: a reprise of the 2008 clash between Federer and Nadal, which produced what many believe is the greatest match in tennis history.
Djokovic is back in the locker room and he will be saying "thank you very much".
When Federer gets up 2-0, you don't think it's going to be a full five sets.