Andy Murray advanced to the semi-finals of the Miami Masters after his last-eight opponent Andy Roddick was forced to retire through injury.
Murray was on course for the first set when Roddick retired
Murray had just broken the American in the eighth game to lead 5-3 when Roddick withdrew.
Roddick had earlier received treatment from the trainer on a hip injury.
The British number one will now have a day off before meeting Novak Djokovic in the last four, after the Serbian upset second seed Rafael Nadal.
The Scot made a determined start against the world number three with a forehand winner in the opening point of the match followed by a delicate drop.
Murray then had two break points in the second game of the opening set but Roddick got out of trouble with his powerful service game.
I'm definitely looking forward to the semis. I'm in good shape and I've got a lot of rest time and I'm feeling good going into it
The game continued with serve but Roddick was struggling with his injury and he required off-court treatment at 4-3.
The American was able to continue but his first contribution after the resumption was to send a smash into the net.
Murray seized his chance, breaking Roddick immediately, but that was the final act of the match.
"I started very well but Andy was struggling badly with his injury and it was unfortunate that he had to pull out," said Murray.
"I'm definitely looking forward to the semis. I'm in good shape and I've got a lot of rest time and I'm feeling good going into it.
"Last year I lost a lot of close matches but this year I'm working hard on winning those sort of matches more often and it is paying dividends."
Despite the injury, Roddick remains hopeful of playing for the US in next week's Davis Cup tie against Spain.
"That's obviously playing a part in this process. I'm just kind of concerned about that," he said.
"I think the medical term for the injury is 'the bottom of my ass hurts,'" he added.
That this is the biggest, and probably the most important victory in my career
"He hit a volley behind me and I kind of lunged at it and jarred something.
"More and more it started becoming like a sharp pain and then I started feeling it even when I was just kind of cruising around the court, not even in points.
"It wasn't getting better. It was getting worse, which isn't a good sign."
After losing to Nadal in last week's final at Indian Wells, Djokovic took quick revenge with a 6-3 6-4 victory in Miami.
Djokovic beat Murray in the Indian Wells semi-finals and has a 2-0 record against his fellow 19-year-old, who is a good friend.
"I have to say that this is the biggest, and probably the most important victory in my career, and he's the best player I ever won against," Djokovic told the ATP website.
"I'm expecting a really, really good match [against Murray]. I mean again, we're playing semi-finals two Masters Series in a row. He is probably fitter than in the last one."
Nadal said: "The big difference is I wasn't playing the same like the final at Indian Wells but he has less mistakes."