Angelique Kerber isn't satisfied with strolling to the No. 1 ranking.
The 29-year-old German will take over the top rating at the end of the BNP Paribas Open due to Serena Williams' injury absence, but in the meantime, Kerber is looking to win the tournament in Indian Wells, Calif.
She took a step in that direction Monday, though it wasn't easy, as she edged France's Pauline Parmentier 7-5, 3-6, 7-5 in a third-round match.
Parmentier, ranked 62nd in the world, was up 4-1 in the final set before Kerber rallied.
"I think I was starting to believe in myself again and trying to take this challenge and trying to play point by point," Kerber, who is seeded second, said of her comeback. "I was not thinking about what has happened before, just going for it and trying to move in good, bring a lot of balls back, and going for it when I have the chance."
Kerber advances to a fourth-round matchup with 14th-seeded Elena Vesnina. The Russian also needed three sets to advance, topping 25th-seeded Timea Babos of Hungary 6-4, 1-6, 6-4.
The day's biggest upset came from 28th-seeded Kristina Mladenovic of France, who eliminated fourth-seeded Simona Halep of Romania 6-3, 6-3.
"I perfectly played the game plan I had," Mladenovic said. "Solid at times, make her play balls and making her take some risk. Sometimes when I had the shorter (ball) stepping in, (I was) playing my heavy shots with the forehand. I think that worked pretty well today."
Mladenovic will face an unseeded American, Lauren Davis, in the fourth round. Davis, a 23-year-old Ohio native and Florida resident, beat Germany's Julia Goerges 6-1, 6-4.
Ninth-seeded American Madison Keys routed Naomi Osaka of Japan 6-1, 6-4. Keys earned a fourth-round matchup with 13th-seeded Carolina Wozniacki of Denmark, who beat Katerina Siniakova of the Czech Republic 6-3, 6-1.