Hailey Baptiste saved six match points as she stunned world number one and defending champion Aryna Sabalenka in the quarter-finals of the Madrid Open.

Baptiste, the 30th seed, came through 2-6 6-2 7-6 (8-6) in a little over two and a half hours to end Sabalenka’s 15-match winning streak.

She is just the second player, after Elena Rybakina in the Australian Open final, to defeat the Belarusian this season.

“I played her a few weeks ago [in Miami] and it was a close match. I had a better idea of how to play her and adjustments I needed to make,” Baptiste, 24, said.

“It was an uncomfortable situation for her, me serving and volleying, hitting a drop shot in one of the match points. It’s not the easiest position to put her in, which is the plan.”

After dropping the first set, Baptiste converted three of her four break points in the second to force a decider.

Trailing 5-4 in the third, the American saved five match points before earning the opportunity to serve for the match after breaking Sabalenka for a third time in the set.

Sabalenka broke back and later brought up a sixth match point at 6-5 in the tie-break. However, Baptiste rattled off three consecutive points to complete her maiden win over a top-five player.

She will face world number nine Mirra Andreeva, of Russia, who beat Canada’s Leylah Fernandez in straight sets, in the semi-finals.

“She played really brave tennis on those match points,” Sabalenka said. “In the first game of the second set, I double faulted twice out of nowhere. That gave her belief. She started playing aggressively. What can I say? Well done.”