Carla Suarez Navarro overcame a rampant Venus Williams to progress to the Miami Open semi-finals, where she will meet Andrea Petkovic.
Suarez Navarro, seeded 12th, was blitzed in the first set but saw off three-time Miami champion Williams 0-6 6-1 7-5 to reach the last four of a WTA Premier event for the first time on Tuesday.
The Spaniard did not hit a winner in the first set, watching on as Williams compiled 14 as the American 16th seed continued her flawless campaign in which she had not lost a set.
But Suarez Navarro dug deep, storming to a 4-0 lead and breaking Williams again to seal the set and square the match.
The pair went game-for-game in the decider, despite four of the first six games going against serve - before Suarez Navarro affected the decisive break in the 12th game.
Suarez Navarro will take on German ninth seed Petkovic for a spot in the Miami final, after the latter had a comparatively comfortable win over 14th seed Karolina Pliskova 6-4 6-2.
Petkovic led 4-1 in the first set over her less-experienced opponent, but Pliskova stormed back into the match - levelling it at 4-4, and holding three break points in the ninth game.
But after Petkovic weathered the storm to hold for 5-4, Pliskova meekly surrendered - dropping serve to love, and starting slowly in the second set.
Petkovic led 3-0 for the loss of just two points, and she did not look back from there.
Suarez Navarro and Petkovic are tied at 2-2 in their head-to-head meetings - all of which have been played on hard courts.
They were set to meet in the final of the WTA Tour event in Antwerp earlier in 2015, but the Spaniard withdrew due to injury.