Andy Murray set to face John Isner in French Open fourth round

Murray is going for a sixth straight win against John Isner

Britain's world number two Andy Murray faces big-serving American John Isner on Sunday for a place in the French Open quarter-finals.

Murray, 29, will be seeking a repeat of the form that saw him overcome Ivo Karlovic in the third round on Friday.

But Isner is a much stronger all-round player than Karlovic and has pushed Murray hard in previous meetings.

The match is scheduled third on Court Suzanne Lenglen but could be delayed because of rain.

• Sunday's order of play

• Roland Garros weather forecast

The American, seeded 15th, accepts Murray would have benefitted from his match against Karlovic.

"He's definitely got some reps in against a pretty big serve," he said. "But my serve is a little bit different. I think I can back it up better, as well.

"He's played the big points better than me, which is one of the reasons why he's number two in the world. So I'm going to have to step up when I get opportunities - if I get them.

"It's a match I would love to win, and a match I believe I can win."

Isner has smashed 92 aces so far at this year's French Open - more than any other player

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