By Piers Newbery
BBC Sport at Wimbledon
An injured Serena Williams battled to an incredible 6-2 6-7 (2-7) 6-2 win over Daniela Hantuchova in the fourth round at Wimbledon on Monday.
Williams looked down and out after dropping the second set
The American was barely able to run at some stages because of a calf strain, and she dropped the second set when the pair resumed after a rain break.
But Hantuchova failed to take advantage as Williams went for big serves and winners at every opportunity.
And it was Williams who broke in game six before serving out for victory.
"I never had an injury like this ever, ever," said Williams. "I didn't know what it was. When I went down I didn't expect to be able to get up."
Despite an early rain break everything had been going smoothly for seventh seed Williams, who raced through the opening set.
I just decided at one point it was over and I was going to die trying
Hantuchova, the 10th seed from Slovakia, recovered at the start of the second and moved into a 5-2 lead but when Williams levelled the end looked in sight.
She had shown no sign of an injury, quite the opposite, when she flinched at 6-2 5-5 while walking along the baseline, tapped her calf with her racquet and fell to the ground.
The umpire, the trainer, Hantuchova and several other official as gathered round as the injury break became longer, and a tearful Williams shrieked in agony when ice was applied to her calf.
With the sky darkening overhead, and Williams' father Richard urging her on from the players' box, the American battled on gamely despite barely being able to walk.
Hantuchova made a poor job of exploiting the injury, putting several balls into the net or out of court, and she led by a relatively slender margin when the weather took yet another turn for the worse.
The players returned after nearly two hours, during which Williams received more treatment and heavy strapping, but Hantuchova soon wrapped up the second-set tie-break.
Williams was hobbling around Centre Court but competed bravely in the decider, stretching between points, and it was Hantuchova who failed to handle the situation.
The Slovakian dropped serve in a tight sixth game and a fired-up Williams held on to set up a quarter-final against top seed Justine Henin.
"It's definitely among my gutsiest matches," Williams said afterwards. "I had little to no movement. It was all about hanging in there, hitting aces and going for it.
"I just decided at one point it was over and I was going to die trying, I was not going down to day - there's no way. I figured my heart wouldn't give out."
It's hard to play against somebody you know is struggling but in the third set I don't think there was anything wrong at all
Hantuchova blamed herself for the defeat and said: "I think I lost it. I had my chances. Maybe if I would have kept the ball in play a little longer, had been a little more patient, that could have been different.
"It's so hard to play against somebody that you know is struggling, and you kind of feel sorry. At the same time you have to be tough and still play your game.
"Well, in the third set, I don't think there was anything wrong at all. I think she was moving very well. I don't think there can be too much wrong when you serve 120 miles an hour. It was definitely a tough set but I still felt like I had my chances, but I didn't take them."