Miami Open 2018: John Isner makes huge claim about his serve ahead of Hyeon Chung clash
JOHN ISNER stunned Marin Cilic to move into the Miami Open quarter-finals - then admitted he hadn’t served better all year.
Miami Open 2018: John Isner says his serve has never been better
Isner arrived in Miami having won just twice all season but that didn’t stop him beating world No.3 Cilic.
Crucial to the 7-6 6-3 win was his monster first serve with Isner not facing a break point all match.
It has set up a last-eight clash with Hyeon Chung and Isner goes into it in confident mood.
He said: "I was very happy with how I played, especially with how I served.
“That's certainly the best I've served all year, today I served exceptionally well and that's what kept me in the match and put scoreboard pressure on him and I finally was able to break through and get a break."
John Isner has ended his poor run by reaching the Miami Open quarter-finals
On a clash with Chung, Isner added: “It's going to be tough. He's found the magic potion this year for sure.
“He's playing incredibly well. It's going to be a very tough match."
Isner and Chung have met three times before with the big-serving American leading the head-to-head 2-1.
Chung needed a little more than an hour to see off the Portuguese Joao Sousa, who could not find an answer to the 19th-seeded South Korean's relentless all-court game.
Marin Cilic was downed by John Isner at the Miami Open
With the win, Chung advances to his second consecutive quarter-final after also making the last eight in Indian Wells, where the 21-year-old lost to Swiss Roger Federer.
Miami Open 2018 quarter-finals
John Isner v Hyeon Chung
Juan Martin del Potro v Milos Raonic
Alexander Zverev v Borna Coric
Pablo Carreno-Busta v Kevin Anderson