Roger Federer found it hard to explain his shock quarter-final loss to South African Kevin Anderson at Wimbledon on Wednesday.
The 36-year-old defending champion was a point away from a 12th consecutive straight-sets victory at the All England Club but ended up losing a cliffhanger 2-6 6-7(5) 7-5 6-4 13-11.
“Honestly, I’m not sure,” the 20-times Grand Slam champion said when asked where it had all gone wrong. “I guess there was definitely a moment at some point. Is it missing match points? Is it getting broken at 5-5 after that?
“I’m not sure. That could have been a key. Could have been a key later. There’s a lot of little points here and there that always make a difference in the outcome of a match.”
It was an extraordinary turnaround after Federer won the first set in 26 scintillating minutes against a player he had beaten four times out of four without dropping a set.
Top seed Federer had a match point in the 10th game of the third set but made a hash of a backhand and nearly two hours later he trudged off a beaten man.
“I was very happy that I got off to the right start, was able to take control somewhat,” Federer said. “I just don’t know exactly how I couldn’t create more opportunities once the third set came around.
“I think I had my chances, so it’s disappointing. I mean, no doubt about it. He was consistent. He was solid. He got what he needed when he had to.
“Credit to him for hanging around really that long,” he added of eighth-seeded 32-year-old Anderson.
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 felt good actually. I’ve been there before. I know what kind of energy I need to bring to the fifth,” he said.
“I was able to bring that. To be honest, I didn’t feel mental fatigue. Even at 10-all in the fifth, it’s all good.
“I still felt like all he needed to do was give me a few second serves, finally pick the right sides again, things could change. I wasn’t horribly negative the whole game.
“It’s just not one of my best days, but they don’t happen very often either. It’s one of those average days you have to try to win the match, and I just couldn’t get it done today.”