John Isner storms into Miami Open semi-finals

John Isner returns the ball during his 6-4, 6-3 win over Japans Kei Nishikori. Picture: Getty

Either world No 1 Novak Djokovic or David Ferrer, who were due to meet late last night, will await Isner, while No 3 seed Andy Murray will take on Tomas Berdych in the other semi-final this evening.

Eighth seed Berdych booked his place against Murray when he claimed a 6-3, 6-4 triumph over Juan Monaco of Argentina. Murray will now face the Czech for the first time since January’s tense Australian Open semi-final when the Scot won through in four sets in a match where Murray’s fiancée Kim Sears apparently aimed an expletive-laden outburst at Berdych’s team.

Isner, meanwhile, has not been broken in the tournament so far. Nishikori, the Japanese star who was barely tested in his first three matches at Key Biscayne, never had a break chance.

The American, 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.

“I played extremely well today,” Isner said after winning in just one hour ten 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 6ft 10in Isner never let 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 whizz past.

Earlier yesterday, Carla Suarez Navarro advanced to the women’s singles final after defeating Andrea Petkovic 6-3, 6-3 in the last four.

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 tomorrow’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 and is looking for her second career title. “It’s a really important tournament for me,” she said. “I just practise all day, all the time during the off-season to play in a final like this.”

Petkovic, the ninth-seeded German, 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. 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 No 1 – were set to play last night to determine the other finalist.