Lukas Rosol pulled off one of the greatest ever upsets in Wimbledon history when he knocked out two-time champion and second seed Rafael Nadal on Thursday.
BBC commentators and fellow players give their thoughts on Rosol's stunning victory under the Centre Court roof.
Defending champion and top seed Novak Djokovic
"There is not much to say aside from the fact that Rosol played an incredible match. I don't think Rafa played that bad but there's not that much he could do.
"You have those days when your opponents have nothing to lose and they're going for all the shots, so congratulations to him. Everybody thought maybe he's going to have some ups and downs in the fifth set, but he proved everybody wrong.
"That's what happens: even though somebody is ranked 100 places lower than you are, on a given day, especially on the grass, if somebody serves that big, anything can happen."
Women's top seed Maria Sharapova
"When the guy's firing missiles left and right, going for broke, I think it's just one of those days.
"I'm sure Rafa feels it was unfortunate he was the one across the net. But that's tennis, we can never underestimate who we're going up against. That's what makes the game so special."
Four-time major champion Kim Clijsters
"I just wanted Nadal to come back and win. I think he did everything right to try to stay in the match, especially in the fifth set, but the guy played incredible.
"For his first time at Wimbledon, it was unbelievable. The decisions he was making, whenever he touched the ball, it was either a winner or an ace.
"I'm curious to see how he's going to play tomorrow because... to me he looked a little bit arrogant out there. I wonder how he'll react in his next match, if he can keep his feet on the ground."
BBC TV commentator David Mercer
"I was an amazing performance. Rafa didn't play that well for the first three sets but he really got it together in the fourth. Then we had the drama of the roof having to be closed. Still, you thought, he's come through the crisis and Rosol, ranked 100th in the world, can't possibly keep up this sort of form. But he did. It was amazing.
"In the final set he played tennis that I've never seen. He was hitting winners at 90mph, one forehand at 99mph. You thought, 'when is this guy going to get nervous', but he didn't.
"In the last game, when he's serving for the match against the two-time champion, he comes up with three aces and a forehand winner. I still find it very hard to believe.
"I've been lucky enough to commentate on Peter Doohan beating Boris Becker and Lleyton Hewitt becoming only the second defending champion to lose in the first round, to Ivo Karlovic.
"But this is right up there because Rafa is such a great fighter, and he fought last night.
"But he was absolutely overwhelmed in the final set. On that form, Rosol would have beaten anybody in the world and that has to be one of the biggest upsets in the history of these Championships."
Former Wimbledon champion Pat Cash
"Would Nadal have won without the break to close the roof? Yes. But the incredible thing is Rosol had 40 minutes to sweat on this. He will have had all sorts of things going through his mind.
"It's usually a classic case of the guy's had a chance to think about this and melts. But he didn't.
"I remember Becker being beaten by Doohan in the second round 25 years ago but since then this is the biggest upset, certainly on the men's side. It doesn't get much better than that.
"The fact that he continued to play that quality of tennis the whole way through just goes to show how good a player he is if it all goes his way. It was pretty amazing. Nadal out of the tournament is good news for every player."
Former British number one Sam Smith
"Jimmy Connors has called a player like Rosol 'a stopper', which means someone who can stop a major seed but isn't going to go deep in the tournament.
"But anybody who saw that last night would think, 'well, maybe he can go a little deeper'.
"I saw a really funny tweet this morning saying 'Rosol' means 'jelly' in Czech. I don't know if that's true but the thing is he was really not like jelly yesterday - he was absolutely fearless, nerveless.
"That's the incredible thing: the script was that he choked at the end, caved in and Nadal won an epic five-setter, but that just didn't happen. It was absolutely extraordinary."
Former British number one John Lloyd
"Rosol's win was stunning, there was no logic to it. He has played four Challenger [events] this year and got to the semi-finals of one. Those are Challengers! Incredible.
"I think it's the biggest ever shock here - and it's the manner in which he did it. Nadal arrived here just having won the French Open and he was taken apart."