Kristina Mladenovic has outlasted Caroline Wozniacki 3-6 7-6 (7-4) 6-2 to reach the semi-finals of the WTA tournament in Indian Wells and break into the top 20 in the world rankings for the first time in her career.

Neither Mladenovic nor Wozniacki had dropped a set before their quarter-final on Thursday.

Wozniacki rallied from a 4-2 deficit in the second set to force the tiebreaker, but the former world No. 1 and 2011 Indian Wells winner never led in the tiebreaker.

Wozniacki held for a 2-1 lead in the third set and then had her right foot heavily taped by a trainer.

She went on to lose the final five games and the match, making the 28th-seeded Mladenovic the lowest seed to reach the semis.

There were 11 service breaks in the two-hour match played in 32C heat.