John Isner through to Miami Open semi-finals

Isner produces a serving masterclass, winning 31 of his 32 first-serve points, to reach last four in Florida

By Raz Mirza

23:14, UK, Wednesday 28 March 2018

John Isner made it through to the semi-finals at Crandon Park with an impressive display

Big-serving American John Isner continued his fine form at the Miami Open with an impressive display to rout Hyeon Chung and reach the semi-finals.

After winning just two matches prior to the Masters 1000 tournament in Florida, Isner has now won four matches in a row thanks to a 6-1 6-4 victory.

Isner, who dumped out second-seeded Croatian Marin Cilic on Tuesday, ran the 21-year-old South Korean ragged in the 68-minute contest.

It's so demoralising when you're up against somebody who is serving that big and also with such variety. Sometimes he's throwing in that slow kicker out to the backhand side on the ad court, then he'll suddenly take it through the court, it's out wide, it's down the centre T. You just keep walking side to side and he was walking through every service game in about a minute-and-a-half. It was one of those matches that became an absolute nightmare [for Chung].
Annabel Croft on John Isner

Chung, playing in his sixth quarter-final of the year, defeated Isner in their previous meeting in Auckland but was unable to stay in the match after being steamrolled in an opening set that saw him broken for the first time this tournament.

"This whole tournament, after each match I've played I've continued to get stronger," Isner told Sky Sports. "The certainly bodes well for the future of the tournament for me. Physically there's absolutely no issues for me, I'm playing as well as I have in a very, very long time so very happy to be in the semi-finals and I do believe I can go further."

Later, Juan Martin del Potro takes on Canada's Milos Raonic in a repeat of their Indian Wells semi-final which the 29-year-old from Argentina won as he aims to make it 15 wins in a row.

"I know whoever I play it's going to be extremely tough," added Isner. "Del Potro is playing the best tennis in the world right now, that cannot be argued, and Milos has found his game after a pretty rough 2017 for his standards. These are the two heavyweights of the game going at it, it's going to be a good tussle for sure."

You can watch more ATP Masters 1000 action from the Miami Open when we continue our coverage on Thursday from 8pm on Sky Sports Mix, which you can find on channel 287, and is free for all Sky customers, and the Red Button on Sky Sports Arena.

Keep up to date with the latest on www.skysports.com/tennis with news, previews, live blogs, reports and expert analysis. On the move? Head to our app for mobile devices and iPad, or follow our Twitter account @SkySportsTennis to join in the conversation.