Summary John Isner defeated Kei Nishikori 6-4, 6-3 to book a spot in the Miami Masters semi-finals.
MIAMI (AFP) - 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.
"Things just snowballed for me," Isner said. "For starters, I can t ask for better conditions out there. I absolutely just can t.
"With the balls, the court, the balls bouncing high, it s hot, it s not that humid so it s not taking a lot out of me. It s perfect conditions for me.
"I just played well," he added. "I ve been serving well really for a while now, and I did that again today. I was taking care of my serve. I was taking my chances on his serve, and the ball was finding the right spots for me."
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.
