Simona Halep fought the wind and a pesky opponent to reach the semi-finals of the WTA Indian Wells Masters on Wednesday.

The world’s top-ranked woman outlasted Petra Martic of Croatia 6-4 6-7 (9-7) 6-3 and improved to 18-1 in matches this year.

Winds gusting to 15 mph made shots tricky. Trailing 4-2 in the first set, Martic closed to 5-4 before Halep served it out.

Martic controlled the second set, taking a 5-2 lead before Halep forced the tiebreaker.

The Romanian tied it at five-all before Martic won the final two points to force a third set. Halep rallied from a 2-1 deficit to tie it at three-all before winning the last three games.

“I was a little bit frustrated about the game today because the wind didn’t give us the rhythm,” Halep said in an on-court interview. “That’s maybe why I’m here because I refuse to lose.”

Halep next plays the winner of a quarter-final between No. 5 seed Karolina Pliskova of the Czech Republic and Naomi Osaka of Japan.