No. 18 seed Madison Keys twice came from behind to topple No. 3 seed Coco Gauff 7-6 (4), 4-6, 6-4 in an all-American fourth-round battle at the Mutua Madrid Open on Monday in Spain.
In a match that needed two hours and 30 minutes, Keys stormed back from a 5-2 deficit in the first set to take a 6-5 lead, only for Gauff to force the tiebreaker. Keys trailed 3-2 before winning five of the last six points.
Gauff rebounded to take the second set and staked a 4-2 lead in the third before Keys rallied again, winning the final four games of the match.
"I definitely had to stay tough," said Keys, who saved 8 of 15 break points while breaking Gauff seven times. "Being able to just stay calm and trust myself, and get myself out of tough sets was really important. I was just trying to take the opportunities when they presented themselves."
Keys benefited from Gauff's 13 double faults.
It is Keys' first bid into the quarterfinals in Madrid. She will face No. 8 seed Ons Jabeur of Tunisia, who cruised past No. 9 Jelena Ostapenko of Latvia 6-0, 6-4.
The other barnburner match of the day saw Belarusian second seed and defending champion Aryna Sabalenka end No. 13 seed Danielle Collins' winning streak at 15 matches. Sabalenka came from behind for a 4-6, 6-4, 6-3 win.
Collins had a 5-4 edge in aces, but Sabalenka saved 7 of 11 break points and broke Collins' serve 6 of 9 times. Collins, a 30-year-old who plans to retire at the end of the season, had begun her streak by winning the WTA 1000 event in Miami and followed that up with a clay-court title in Charleston.
Collins led 4-3 in the second set before Sabalenka found a new gear, winning the next six games in a row.
Sabalenka's quarterfinal opponent will be Russian teenager Mirra Andreeva, who upset 12th-seeded Italian Jasmine Paolini 7-6 (2), 6-4.
No. 1 seed Iga Swiatek of Poland had little trouble defeating Spain's Sara Sorribes Tormo 6-1, 6-0 in just 67 minutes. Her next opponent will be No. 11 Beatriz Haddad Maia of Brazil, who knocked out Greek fifth seed Maria Sakkari 6-4, 6-4.
Finally, No. 4 Elena Rybakina is set to face Kazakh countrywoman Yulia Putintseva in the quarters. Rybakina beat the Czech Republic's Sara Bejlek 6-1, 6-3, and Putintseva upset No. 10 seed Daria Kasatkina of Russia 3-6, 6-2, 6-2.
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