Three-time champion and eighth seed Venus Williams has been knocked out of the Miami Open in the quarter-finals by qualifier Danielle Collins.

The 24-year-old, ranked 93rd in the world, needed only one hour 29 minutes to come through 6-2 6-3 against fellow American Williams, 37, a seven-time Grand Slam winner.

It was Collins’ first victory against a top 10 player.

She will now face French Open champion Jelena Ostapenko in the semi-finals.

The 20-year-old Latvian saw off world number four Elina Svitolina over two tie-breaks, winning 7-6 (7-3) 7-6 (7-5).

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“The first time I saw Venus in the locker room I nearly cried,” Collins admitted. “She has been my favourite player so I am finding it difficult to wrap my head around this.”

Victoria Azarenka will play US Open champion Sloane Stephens in the other women’s singles semi-final.

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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.

• Live scores, schedule and results
• Venus Williams knocked out by qualifier Danielle Collins in Miami

“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.