Reigning Australian Open champion Madison Keys was broken while serving for her third-round Madrid Open victory at 5-4 in the second set against Anna Kalinskaya, but recovered to complete a 7-5, 7-6 (7/3) in one hour and 48 minutes on Saturday.
The fifth-seeded Keys lost to Kalinskaya earlier this month in Charleston.
"I knew I had to raise my level after getting a bit of spanking last time," said Keys.
A semifinalist in Madrid 12 months ago, Keys awaits her compatriot Emma Navarro or Croatia's Donna Vekic in the round of 16.
American fourth seed Coco Gauff eased past compatriot Ann Li 6-2, 6-3 to set up a last-16 clash with Swiss Olympic gold medallist Belinda Bencic.
Seventh-seeded teenager Mirra Andreeva continued her impressive form at WTA 1000 tournaments this season by storming into the fourth round with a 7-5, 6-3 performance against Polish 27th-seed Magdalena Frech.
The 17-year-old Russian, who won back-to-back titles in Dubai and Indian Wells, will take on Ukrainian qualifier Yulia Starodubtseva for a shot at reaching a second consecutive Madrid quarterfinal.