By Chris Oddo | Thursday, April 2, 2015

John Isner displayed peak form on Thursday in Miami, which meant to a large degree that Kei Nishikori didn’t get the chance to display what kind of form he was in. Isner took the racquet out of Nishikori's hands early and often, putting forth a barrage of big serves and bigger forehands to pummel the world No. 4, 6-4, 6-3.

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“I think he close his eyes and hitting so many winners,” Nishikori would later say. “Couldn't really stop him today.”

Nishikori did hold his own for much of the first set, but once Isner rallied from 0-30 down at 4-all then broke to love to take the opener, the floodgates were open.

“I mean, it doesn't happen for me as much as it happens for a guy like Roger or Novak,” Isner said of his torrid stretch. “I can probably count on one hand the times I've gotten in a groove like that. But it feels good. I was down Love 30 at 4 All. When I was able to break at 5 4, took a lot of pressure off me.”

Isner broke to love again in the second game of the second set, and he had the better part of the rallies for the rest of the way, even though Nishikori managed to stay close by saving a few break points midway through the set.

Nishikori, who came into the quarterfinals scorching hot with three dominant wins that saw him earn 15 breaks of serve in 23 return games, never could get in sync against Isner’s massive serve and fusillade of groundies.

“I think the big reason is he doesn't give you good rhythm in your strokes,” Nishikori said. “He tries to hit winners from everywhere, so there is no long rallies. For me, it's tough to have good rhythm my strokes.” He added: “And also, he was serving great today. So, yeah, I need a little more focus on my first service game, and that's something I to have work on next time.”

Isner hammered 13 aces and dropped only 11 points on serve, never facing a break point.

He will move on to face either Novak Djokovic or David Ferrer in Friday’s semifinals. After notching his first Top 10 win in nearly two years over Milos Raonic in the round of 16, the American has now earned back-to-back Top 10 wins four times in his career.

The victory also improves Isner’s career record in Masters 1000 quarterfinals to 6-0. The American, currently ranked No. 24 in the world, has gone 2-3 in his previous five semifinals at the Masters level.