Alexander Zverev said he was "on one leg today" after Taylor Fritz mounted a stirring comeback from two sets down to dump the fourth seed out of Wimbledon.
Zverev appeared to be cruising towards his first quarter-final at the All England Club before an inspired Fritz turned the match around, winning 4-6, 6-7 (4/7), 6-4, 7-6 (7/3), 6-3.
The American 13th seed's break in the third set was the first time big-serving Zverev had been broken in the entire tournament.
Fritz then won the fourth-set tie-break to level the match before breaking again early in the decider.
"It was amazing to do that on Centre Court, two sets down in front of this crowd. It's a dream," he said.
"The thing was I still felt I was playing really well for being down two sets. I was just thinking it sucked to be playing this well and to lose in straights.
"So let's take the third, I took it one at a time. I had that belief. It was just a couple of points here and there."
The American, who hit a total of 69 winners against 23 unforced errors, will face Italian 25th seed Lorenzo Musetti in the quarter-finals.
Zverev said he had struggled physically as a result of a knee injury he picked up in his win against Cameron Norrie.
"I was on one leg today," said the German, who played with a support on his left knee.
"It is nothing that I need surgery on," he added. "It is nothing that doesn't heal by itself. It just needs time.
"I do know that also I had a great opportunity here at Wimbledon. I didn't want to pull out. Yesterday I couldn't practise at all. Yesterday I couldn't walk even.
"Today I felt much, much better. That's why I did try to play. I also knew I did have a great opportunity this year at Wimbledon. It's the best I've probably ever felt on the Wimbledon courts."
The 27-year-old, who was runner-up at the French Open last month, played down fears he would not be able to defend his Olympic title at the upcoming Paris Games.
"I have three weeks," he said. "From what I understand, it's going to be fine in a shorter period of time."
Zverev expressed frustration over the behaviour of some people in Fritz's box, speaking to the American at the net at the end of the match.
"His team is extremely respectful. I think his coach, his physio, also his second coach, they're extremely respectful," he said.
"I think there's some other people that maybe are in the box that are not maybe from the tennis world, that are not maybe from particularly watching every single match. They were a bit over the top."
D.Jayaraman--BD