When Draper needed medical attention at the end of the second set against American Giron, and disappeared off court after the third, it looked to be a familiar tale.

The 22-year-old has been plagued by a host of physical problems and early retirements in his burgeoning career.

Playing in stifling temperatures on the hottest day of the tournament so far, Draper appeared in deep trouble when he trailed by two sets to one.

Instead, he recovered admirably to earn what he said was one of his most gratifying victories.

"Last year, there was a lot of matches where I felt like I was sort of not getting physically any better. As time went on, it just wasn't coming," he said.

"This year, I'm obviously nowhere near where I want to be still, but it's coming. For sure I would have cramped in these matches last year, even maybe four months ago.

"There is a lot of positives. I have to be honest with myself and say that I am improving on that side of things."

Draper won eight games in a row to turn the match in his favour and managed that, with instructions from his team to try to keep the points short, by using more variety with serve and volleys, slice and drop shots.

In the decider, Draper broke again for 4-2 after outlasting and outthinking Giron in a brilliant exchange on break point.

That left the Briton bent over the side of the court to catch his breath and his physical exertions were illustrated even more starkly when he clinched victory.

After stretching for a forehand winner on his first match point, Draper shook hands with Giron before immediately running over to a courtside bin to be sick.

"I don't usually get sick, it's weird," Draper said. "It was obviously a physical match and tough conditions, but it wasn't that long for a five-set match.

"I think it's tougher in a Grand Slam with the tension, to play that first match. I'm still a young player, so getting used to the environment around these Slams and the tension is difficult.

"I felt better in the fifth set than I did the first."