Juan Martin del Potro survived a three-hour encounter against Canadian Milos Raonic to book a Miami Open semi-final meeting with John Isner.

The Argentine fifth seed came through 5-7 7-6 (7-1) 7-6 (7-3), in a match that finished at midnight local time.

Former US Open champion Del Potro claimed his maiden Masters 1,000 title in Indian Wells earlier this month and is now on a 15-match winning streak.

Isner eased past South Korean Chung Hyeon 6-1 6-4 to reach the last four.

The big-serving American hit 13 aces to overcome 19th-seed Chung in only 68 minutes.

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“I played extremely well and every match I have gotten better and stronger,” said 32-year-old Isner, seeded 14th.

“I know I’m in the semi-finals and I can’t wait to get back on this court. Del Potro is the hottest player on tour right now, hands down,”

The other men’s quarter-finals will be played on Thursday when South African sixth seed Kevin Anderson faces Spanish 16th seed Pablo Carreno Busta, before German fourth seed Alexander Zverev takes on Croatian Borna Coric.

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Britain’s Andy Murray says he is making “progress” after several days of playing at the Mouratoglou Academy in Nice.

Murray returned to the court for the first time at the weekend after having hip surgery in January.

The former world number one has not played a competitive match since he was knocked out of Wimbledon last July.

The ongoing problem had forced the Scot to pull out of the Australian Open at the start of the year.

Murray, 30, posted pictures on Instagram in practice against British junior Aidan McHugh.

He is expected to stay in Nice for at least another week as he continues his comeback.

Three-time Grand Slam winner Murray has fallen to 29 in the world and has been overtaken by Kyle Edmund as Britain’s number one.

Victoria Azarenka booked her place in the semi-finals of the Miami Open with a 7-5 6-3 win over Karolina Pliskova.

The Czech fifth seed, 26, recovered from going two breaks down to level at 5-5, before Belarus’ Azarenka took the opener on her fifth set point.

The pair exchanged breaks in the second set before the three-time champion pulled through.

Azarenka, 28, will meet Sloane Stephens in the last four, after the American’s win over Angelique Kerber.

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Stephens, the 2017 US Open champion, brushed aside the German former world number one 6-1 6-2 in just over an hour to advance to her first semi-final since her victory in New York.

It means the 13th seed will be named in the world’s top 10 when the rankings are released next week.

“I am so tired of hearing that I am number 11 in the world,” said the 25-year-old.

“It’s very exciting to get there, something I have wanted to do for a while. Getting into the top 10 is pretty special and something I have worked on for a long time.”

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