INDIAN WELLS (AFP) — American Emma Navarro shocked Australian Open champion Aryna Sabalenka to reach the Indian Wells ATP-WTA Masters quarterfinals while Coco Gauff sailed through.

Navarro, ranked 23rd in the world, pushed Sabalenka hard on a breezy Stadium Court to notch her first career win over a top-five player 6-3, 3-6, 6-2.

US Open champion Gauff, seeded third, celebrated her 20th birthday with a dominant 6-0, 6-2 victory over Belgian Elise Mertens.

It wasn't quite so easy for last year's men's runner-up Daniil Medvedev, but the fourth-seeded Russian managed the windy conditions to post a 6-4, 6-4 triumph over Bulgarian Grigor Dimitrov.

Medvedev next faces seventh-seeded Holger Rune, who saved a match point then roared through the second-set tiebreaker on the way to a 2-6, 7-6 (7/2), 6-3 victory over 2022 champion Taylor Fritz.

"It was a crazy match," Rune said.

"I managed to raise my level in the end of the second set. I just kept believing. I was always behind in the match, I was struggling to break his serve, but once I found my rhythm, especially the tiebreak was very good for me and then I just gained confidence."

Medvedev said consistency was the key to his victory in windy conditions.

"I think in general I played well. I was really consistent," said Medvedev, who had just 13 unforced errors as he moved a step closer to a first title at Indian Wells — the only hardcourt ATP Masters tournament he has never won.

In other men's matches, American Tommy Paul ended Italian Luca Nardi's dream week with a 6-4, 6-3 victory.

Nardi, who lost in qualifying but gained a place in the main draw as a "lucky loser" thanks to a withdrawal, was coming off a stunning upset of world number one Novak Djokovic in the third round.

Paul will play for a place in the semi-finals against ninth-seeded Casper Ruud, who rallied to beat French veteran Gael Monfils 3-6, 7-6 (7/3), 6-4.

Navarro's victory over world number two Sabalenka continues a strong season for the 22-year-old, who won the WTA title in Hobart and reached the semi-finals in Auckland and San Diego.

"It's definitely cool to be able to play an opponent like that and feel like I can hang and I can win," she said.

"I've worked really hard over the years to kind of just get to this point and be able to play at a level that can compete with the best players in the world."

"I think that showed today," she added.

Sabalenka, meanwhile, has found it frustrating since her successful title defense at the year's first Grand Slam. The Belarusian's fourth-round exit follows her opening-match defeat in Dubai last month.

After the two exchanged just two breaks of serve in the first two sets, Navarro came out ahead as they traded three straight breaks in the third to take a 3-1 lead.

She broke Sabalenka again to seal the match, finishing with 22 winners to 14 unforced errors while Sabalenka's 38 winners were countered by 34 unforced errors.

Sabalenka, who saved four match points to win her opener against 64th-ranked American Peyton Stearns, acknowledged that she never really got comfortable in the California desert this year.

"I tried to adjust," she said.

"I would say that we did our best and we'll learn."

Navarro next faces face ninth-ranked Maria Sakkari of Greece, a 6-2, 3-6, 6-3 winner over France's Diane Parry.

Gauff, who turned 20 on Wednesday, will next face China's Yuan Yue, who beat Daria Kasatkina 4-6, 6-4, 6-3.

"Feels good — finally got a win on my birthday," Gauff said after what she called a "pretty straightforward" victory.