KEY BISCAYNE, Fla. (AP) — Once John Isner started rolling, Kei Nishikori was simply overmatched.
With an array of booming serves and blasted forehands, Isner powered his way into the semifinals of the Miami Open on Thursday with a 6-4, 6-3 win over the fourth-seeded Nishikori. He became the first American man to reach the final four on Key Biscayne since Mardy Fish in 2011.
Either world No. 1 Novak Djokovic or David Ferrer will await Isner, who was serving at 4-4, 0-30 in the first set — then ripped off the next 11 points and 19 of the next 21 to take control.
Isner has not been broken in the tournament. Nishikori, the Japanese star who was barely tested in his first three matches at Key Biscayne, never had a break chance Thursday.
"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 today. I'm very, very happy."
Isner 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 as the 6-foot-10 Isner never let the 5-foot-10 Nishikori get anything going.
"It's just perfect conditions for me," Isner said. "I can't ask for better weather. The ball's getting up high, it's moving through the court fast."
When Isner stepped into one forehand return early in the second set and put it down the line for a winner, all Nishikori could do was shrug his shoulders and watch the ball whiz past.
Earlier Thursday, Carla Suarez Navarro advanced to the final at the after topping Andrea Petkovic 6-3, 6-3 in a semifinal matchup.
Like Isner, the 12th-seeded Spaniard didn't face a single break point and will meet either top-seeded Serena Williams or third-seeded Simona Halep in Saturday's final.
It's the eighth time Suarez Navarro has reached a WTA final. She is the first Spanish woman to make the final at Key Biscayne since Arantxa Sanchez-Vicario in 1993. She's looking for her second career title.
"It's a really important tournament for me," Suarez Navarro said. "I just practice all day, all the time during the offseason to play in a final like this."
Petkovic, the ninth-seeded player from Germany, lost to Suarez Navarro for the third time in five meetings. Petkovic had not dropped a set in any of her first four matches this year at Key Biscayne.
Suarez Navarro took control of the opening set with an early break, then broke Petkovic again when the German's forehand sailed well long to end the set. And in the second, Suarez Navarro broke yet again for a 4-2 lead and finished it off not long afterward.
Suarez Navarro had been pushed to three-setters in each of her previous two matches. She threw her fists in the air and smacked a ball into the stands with joy when Petkovic's final shot sailed wide.
Williams and Halep — the last woman to beat the world's No. 1 — were set to play Thursday night to determine the other finalist. That match follows the Djokovic-Ferrer quarterfinal.
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