American John Isner rained down 13 aces in a dominating performance to defeat Japan's Kei Nishikori 6-4, 6-3 and book a spot in the Miami Masters semi-finals on Thursday.
Isner, whose year has been modest at best, has exploded into form on the hardcourts of Miami, where he has yet to drop a service game.
He ended the hopes of world number five Nishikori, Asia's top player who reached the US Open final last September. It was Isner's second top-10 win of the tournament, after his upset of sixth-ranked Milos Raonic on Tuesday.
Isner will face a big test in the semi-finals, when he takes on the winner of Thursday night's match between world number one Novak Djokovic and Spain's David Ferrer.
Nishikori had never faced the monster delivery of Isner and was unable to cope with the power off the big man's racquet. Isner delivered his final ace on match point after 70 minutes.
"He played really well today -- everything -- I didn't have any chance," said Nishikori, who managed only five winners while Isner piled on 33.
"His forehand, his backhand, he hit some winners from back of the baseline.
"I couldn't really stop him today. I don't think I really played bad ... but I think he played well today."
Nishikori reached the Miami semi-finals a year ago after beating Ferrer and Roger Federer but was unable to play his scheduled match against Djokovic because of a groin injury.
"It's really disappointing to lose today," he said. "But I had a good three matches here. I think I'm playing good again."
Nishikori suffered only his fifth loss of the season against 20 wins and a title in Memphis in February.
Source: AFP