KEY BISCAYNE, Fla. -- World No. 1 Novak Djokovic of Serbia has reached the semifinals of the Miami Open, overcoming an early break to oust David Ferrer of Spain 7-5, 7-5 on Thursday night.
Djokovic faced a quick 3-0 deficit, then rallied and took control by winning 10 of the next 13 games. He'll play 22nd-seeded John Isner of the United States in the semifinals Friday night.
Powerfully ripping off five straight games at one point, Isner rolled past fourth-seeded Kei Nishikori 6-4, 6-3 becoming the first American man to go that deep in the draw at Key Biscayne since Mardy Fish in 2011.
"I played extremely well today," Isner said after winning in just 1 hour, 10 minutes. "I needed to play well in order to beat a player like Kei and that's what I did. From start to finish, I felt like I was aggressive. I was playing all the right shots and things just went my way."
Isner was serving at 4-4, 0-30 in the first set, briefly flirting with trouble. A few minutes later, it was basically over. He won the next 11 points and 19 of the next 21, at one point leaving Nishikori with no choice but to shrug his shoulders as another winner whizzed past.
"I can probably count on one hand (the times) that I've gotten in a groove like that," Isner said.
He'll try to find the groove again Friday night when he takes on Djokovic, who's won six of their eight previous matchups.
"I'll have nothing to lose," Isner said.
Isner has not been broken in the tournament, had 13 aces on Thursday and won 41 of the 52 points on his serve.
"Serve, I didn't have any chance," said Nishikori, the Japanese star who stands 5-foot-10, a foot shorter than Isner and had broken serve 15 times in 23 return games in his first three matches at Key Biscayne.
The American won the first set on the only lucky break he needed, when a groundstroke clipped the top of the tape and fell just inside the sideline on set point. Everything else was power.
"It's just perfect conditions for me," Isner said.
So he's moving through the Miami bracket, just like Wisconsin, Duke, Kentucky and Michigan State in men's college basketball -- as he predicted.
"I'm prouder of that than how I played today, actually," said Isner, who picked the Badgers to win it all. "No, I'm kidding. I did. It's lucky. But I did."
Djokovic got on a similar roll in his quarterfinal.
Down 3-0 early, he won 10 of the next 13 games and never looked back -- spoiling Ferrer's 33rd birthday.
"A very close match," Djokovic said. "I enjoyed it."
Up 4-2 but facing break point, Ferrer stabbed his racket out to snare a passing try by Djokovic, the resulting drop-shot winner drawing raves from the crowd and even a racket-clap from Djokovic himself.
It was one of the last hurrahs for Ferrer.
Djokovic got the break two points later, putting the opening set back on serve. Another break followed for a 6-5 lead, and Djokovic finished the 58-minute opening set off with a hold.
It was the 31st time he's won a first set at Key Biscayne. He's now 31-0 in those matches. Ferrer fought off a match point and ended up breaking Djokovic to knot the second set at 5-5, then lost eight of the match's remaining 10 points.
"I expected it to be a very physical match as it always is with David," Djokovic said. "He's one of the greatest competitors out there."
The Associated Press contributed to this report.