LONDON (CNN) – Playing in unfamiliar surroundings at Wimbledon, Roger Federer suffered an unfamiliar defeat against a big server who just didn’t flinch on Wednesday.

Federer blew a match point and two-set lead to Kevin Anderson (2-6 6-7 (5-7) 7-5 6-4 13-11) in a four-hour and 14-minute quarterfinal played away from his backyard of Centre Court.

“It’s disappointing losing the next two sets after winning the first two and having match points,” Federer told reporters after the match. “I’ve been there before. I know what kind of energy I need to bring to the fifth. I was able to bring that. I didn’t feel mental fatigue. Now, I feel horribly fatigued and just awful. It’s just terrible. But that’s how it goes. Credit to him.”

It was Federer’s first loss at SW19 since the 2016 semifinal against Milos Raonic. That one, too, went to five sets. Not since 2011 at Wimbledon, against Jo-Wilfried Tsonga, had Federer fallen from two sets up.

Federer shut down his season due to knee problems after that loss and, given some of his errors Wednesday, one had to wonder if the 36-year-old was feeling something physically. Federer did slip in the second set after engineering a stunning lob.

He didn’t mention an injury post-match, but said simply that he was “average,” a word not really associated with Federer.

“It’s just not one of my best days, but they don’t happen very often either,” added Federer. “It’s one of those average days you have to try to win the match, and I just couldn’t get it done today.”

Roger Federer

Roger Federer walks off after losing his match against Kevin Anderson on Day 9 of Wimbledon on July 11, 2018 in London, England. (credit: Julian Finney/Getty Images)

The marathon contest took place on Court 1, the first time that the eight-time champion played at Wimbledon outside of Centre Court since 2015, when he was in the midst of a four-and-a-half year grand slam drought. But there were no such issues for the evergreen Federer entering Wimbledon this year.

Federer had won three of the last four grand slams he contested to lift his tally to 20 overall, and was the favorite to add to that haul come Sunday evening, especially since the world No. 2 hadn’t dropped a set through four rounds — or even his serve.

The fifth-set score was reminiscent of the 2009 Wimbledon final. Federer won 16-14 in the final set over an unfortunate Andy Roddick. Roddick was only broken once that day.

Anderson was not as prolific on his serve, but the U.S. Open finalist wasn’t broken in the final three sets. He saved his lone break point of the fifth at 3-4 with a potent delivery and finished with 28 aces. He broke through at 11-11, aided by Federer double faulting at 30-all.

In the past, the eighth seed has sometimes struggled to close out matches. But there was no issue Wednesday. From 0-15, Anderson held firm. He will now face either Raonic or John Isner in what will be a battle of two big servers. Isner — into his first Wimbledon quarterfinal — leads the event in aces, followed by Raonic.

When Federer broke Anderson in the first game, there were flashes of the 2014 semifinal against Raonic, when he did the same. It set the tone. Breaking for a second time to end the set in 25 minutes, no one could have forecast the drama that was to come.

“First set, felt great,” said Federer. “Reading the serve. He wasn’t getting many aces. When I was on, I was making him play. From the baseline, I felt like I could mix it up, play aggressive.”

“As the match went on,” Federer continued, “I couldn’t surprise him any more. That’s a bad feeling to have.”

Anderson broke for 2-0 in the second set, becoming the first player since Tomas Berdych in last year’s semifinal to take the Federer serve at Wimbledon. But, aided by a majestic defensive lob that turned into a winner right in the corner, Federer broke back for 2-3 and, to add to Anderson’s frustration, he sent a forehand into the net on break point in the sixth game.

How costly was the fall, though? Federer didn’t say.

Winning the tiebreak, Federer appeared to be on his way to victory. Holding match point at 5-4 in the third on Anderson’s serve, a penetrating ground stroke from Anderson forced an error from the top seed.

Federer, atypically, got rattled. He was broken for 5-6 and failed to take advantage of 0-40 on the Anderson serve in the ensuing game. It was becoming a struggle for Federer, and even more so when he was broken at 4-4 in the fourth.

Anderson was looking rock solid on serve and earned a set point, only for Federer to save it with a forehand winner. As the drama heightened, Anderson had to save a break point with a sizzling backhand. But he eventually closed out the fourth with a rocketed backhand.

Federer left the court for a toilet break and a nervy fifth set followed. They each held serve from 0-30 in the seventh and eighth games and Anderson — serving second — dug out of a 0-30 hole at 5-6. Anderson finally broke through at 11-11 and hung on for the biggest win of his career.

For Federer, defeat marked only the fifth time that he had been ousted at a slam after holding a match point.

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