Second-seeded Carlos Alcaraz saw his title defence and 14-match winning streak in Madrid come to an end at the hands of Andrey Rublev in the quarter-finals on Wednesday while top-seeded Jannik Sinner withdrew from the tournament citing a right hip injury.

Rublev upset home favourite Alcaraz 4-6, 6-3, 6-2 to reach the semi-finals.

Alcaraz missed the clay-court tournaments in Monte Carlo and Barcelona last month due to a forearm injury and needed a third-set tiebreak to squeeze past last year's finalist Jan-Lennard Struff in the fourth round on Tuesday.

He couldn't hold off an inspired Rublev though, his quest to become the first man to win three consecutive titles in Madrid coming to a crashing halt.

Sinner was due to face Felix Auger-Aliassime in the quarter-finals on Thursday but revealed he has been battling through a hip issue this week in the Spanish capital.

"My hip has been bothering me this week and has slowly been getting more painful. Taking the advice from the doctors we decided it's best to not play further and make it worse," wrote Sinner in a statement on social media.

Sinner is due to play on home ground at the Italian Open in Rome next week before heading for an assault on the French Open, the season's second major, which starts in Paris on May 26.

Elena Rybakina battled back from 2-5 down in the deciding set and saved two match points to overcome Yulia Putintseva 4-6, 7-6 [7/4], 7-5 and reach the semi-finals of the WTA event.

A late-match collapse from Putintseva, who smashed her racquet and left it on court after the match, helped Rybakina advance to her sixth semi-final of the season, where she will face defending champion Aryna Sabalenka.

Australian Open champion Sabalenka picked up a 10th consecutive victory in Madrid with a 6-1, 6-4 win against 17-year-old Mirra Andreeva.

Sabalenka is 5-3 lifetime against Rybakina but lost three of their last four meetings, most recently in the Brisbane final in January. Their Madrid semi-final will be their first encounter on clay. (AFP)