Carlos Alcaraz has long unbeaten Madrid Open run ended by Andrey Rublev

Carlos Alcaraz's quest for a third successive Madrid Open title was ended by a shock quarter-final defeat to Andrey Rublev.

The reigning Wimbledon champion was on course to extend his winning streak at the tournament to a record-breaking 15 matches after clinching the opening set.

But Russian seventh seed Rublev hit back in stunning fashion to register one of the greatest victories of his career, progressing 4-6 6-3 6-2 in just over two hours.

Asked about the most pleasing aspect of his performance, the 26-year-old told Sky Sports: "That I was able to stay calm all the match. I don’t know how – even me, I’m surprised."

World number three Alcaraz, who in March defended his Indian Wells title, saw the start of his clay court season disrupted by an arm injury which caused him to miss both the Monte-Carlo Masters and the Barcelona Open.

Backed by a partisan home crowd, which included former Spain international footballers David Villa and Raul and Real Madrid star Luka Modric, the 20-year-old began well.

But underdog Rublev swung the momentum by breaking serve in the second game of the second set before dominating the remainder of the contest to set up a semi-final with American Taylor Fritz, who later on Wednesday beat Argentinian Francisco Cerundolo 6-1 3-6 6-3.

Alcaraz’s surprise elimination came a day after compatriot Rafael Nadal, a four-time winner of the competition, crashed out to Jiri Lehecka.

World number eight Rublev, who hit 30 winners under the roof on Manolo Santana Stadium, added: "I just was saying, 'keep playing, keep fighting, keep trying’.

"I had one break in the first set so keep believing in yourself, be more convinced, go for it and maybe you will have more break points.

"In the end, I was able to return well and