Reigning champion Spain's Paula Badosa held off Canadian teen sensation Leylah Fernandez to reach Indian Wells open quarterfinals Tuesday and stay on course for her title defense.

Badosa, seeded fifth, saved five of the six break points she faced and kept last year's U.S. Open runner-up under pressure – converting three of her 12 break chances.

"Today was very tough," said Badosa, who lifted the trophy last October in a tournament moved from its usual March date because of the coronavirus pandemic.

"Leylah is an amazing player, very fast and good timing. I knew I had to fight and serve very well. I think I did that the entire match."

Badosa is vying to become the first woman to win back-to-back Indian Wells titles since Martina Navratilova in 1990-91.

She gained the upper hand in the second set with a break for 3-2, then saved a pair of breakpoints in the eighth game to take a 5-3 lead.

"In the important moments, like 4-3, down the breakpoints, I think I stayed very composed," added Badosa, who next faces Veronica Kudermetova, a 7-6 (7/5), 6-7 (5/7), 7-5 winner over Marketa Vondrousova.

World No. 4 Iga Swiatek, the highest-ranked player remaining in the women's field, rallied from a set down for a third straight match to book her quarterfinal berth, beating crafty German veteran Angelique Kerber 4-6, 6-2, 6-3.

Swiatek, the 2020 French Open champion, is coming off a title in Doha last month, but the 20-year-old admitted it took her a while to figure out how to tackle Kerber – another former Grand Slam champion.

"Truth be told, I wasn't really sure what my tactics should be, if I should be more aggressive or play more patient game," Swiatek said. "But at the end I think I made the right decision in right time, in right moments of the match."

She said Kerber showed her a different game than she'd expected after practicing with the German.

"I felt like she wanted to use her experience and kind of trick me," Swiatek said.

Swiatek next faces American Madison Keys, who beat British qualifier Harriet Dart 6-1, 6-4.

Former world No. 1 Simona Halep of Romania, seeded 24th, swept into the quarterfinals with a 6-1, 6-4 victory over 26th-seeded compatriot Sorana Cirstea.

Halep, a two-time Grand Slam champion is in the quarters for the fifth time at Indian Wells, where she lifted the trophy in 2015.

Halep will play Petra Martic for a place in the semifinals. Croatia's Martic beat Liudmila Samsonova 7-6 (8/6), 6-4.

Sixth-seeded Maria Sakkari of Greece advanced with a victory over Australian qualifier Daria Saville, who was trailing 4-1 when she retired with a left thigh injury.

Sakkari will play Elena Rybakina, who beat Viktorija Golubic 7-6 (7/5), 6-2.

Rublev, Berrettini advance

In the men's tournament, sixth-ranked Matteo Berrettini shook off mid-match doldrums to defeat South Africa's Lloyd Harris 6-4, 7-5 to reach the fourth round while world No. 7 Andrey Rublev powered past American Frances Tiafoe.

The 25-year-old Italian Berrettini, winner of five ATP titles but seeking his first Masters 1000 crown, is the second-highest ranked man left in the draw behind fourth-seeded Rafael Nadal.

But he admitted he'll need to do better after a victory in which he trailed 4-1 in the second set.

"I got a little bit nervous," he said. "I didn't like how I handled the start of the second set. I let the anger out a little bit, which helped."

A dozen aces also helped as Berrettini won five straight games to secure the victory.

Rublev, who has captured titles in Marseille and Dubai this year, pushed his ATP match winning streak to 11 with a 6-3, 6-4 victory over Tiafoe.

American John Isner powered past Argentina's Diego Schwartzman 7-5, 6-3. Isner, who towered over his opponent by 38 centimeters, fired 13 aces and didn't face a breakpoint.

Isner is one of four U.S. men into the last 16 along Taylor Fritz, Jenson Brooksby and Reilly Opelka – who will take on Nadal on Wednesday.