World number two Jannik Sinner survived a stern test from Joao Fonseca on Tuesday to reach the Indian Wells quarter-finals, while women's world number one Aryna Sabalenka eased past 16th seed Naomi Osaka 6-2 6-4 to progress to the women's last eight.
Sinner was pushed hard by the 19-year-old Brazilian, trailing 6-3 in the first set before rallying to close out the match 7-6(6) 7-6(4).
"I am very happy winning this match," Reuters quoted Sinner as saying.
"Joao is an incredible talent. He was serving really well. I was trying to be as aggressive as possible and that was the key to get through against the incredible talent."
The Italian will now meet the home favorite Learner Tien on Friday for a place in the last four.
"I feel he is a very consistent player and I am very happy to face him again. He has improved a lot since the last time we met," Sinner said of his American opponent.
Meanwhile, in the first meeting between the two four-time Grand Slam champions since 2018 - when Osaka beat Sabalenka at the US Open en route to her maiden major title - the Belarusian's power proved too much for the former world No. 1 on Tuesday.
"Yeah that's crazy, for so many years we only played once. I'm pretty sure we are playing many more matches, she's coming back playing great tennis," Sabalenka said in her on-court interview. "I'm pretty happy for the result today, much better than last time."
Osaka began confidently with a strong opening service game, but top seed Sabalenka soon found her rhythm and capitalized on a brief dip from the Japanese, breaking for 2-1 after two double faults.
The Belarusian tightened her grip with a barrage of powerful backhands to lead 5-2, then served out the set comfortably with an ace.
After a series of solid holds from both players early in the second, Sabalenka again used her firepower to take control, breaking again for a 4-2 lead that proved decisive in closing out the win and continuing her run in the tournament without dropping a set.
"I'm happy that I put so much pressure on her today, that I brought variety to the court," Sabalenka said. "My serve worked well. On the return I played really great tennis. Happy with my performance for sure."
Last year's runner-up Sabalenka will continue her quest for a first title in the California desert against Canada's Victoria Mboko, who sailed past higher-ranked American Amanda Anisimova 6-4 6-1.
It will be a rematch of an Australian Open round-of-16 between the two, which Sabalenka won in straight sets.
Elsewhere, Australia's Talia Gibson enjoyed the biggest win of her career, beating Italy's world No. 7 Jasmine Paolini 7-5 2-6 6-1 in her first match against a top-10 player.
The 21-year-old, playing her first WTA 1000 main draw, also became the first qualifier in 11 years to reach the quarter-finals of the tournament.
"I just have a confidence in the way I'm playing," Gibson said. "I'm in shock."
Czech Republic's Linda Noskova, the 14th seed, sailed past Alexandra Eala in just 55 minutes with a 6-2 6-0 win to book a quarter-final meeting with Gibson.
In the men's draw, Alexander Zverev saw off Frances Tiafoe 6-3 6-4, converting two of three break points and firing 14 aces to seal his ninth win over the 21st-seeded American.
He will next face France's Arthur Fils as he looks to reach his first Indian Wells semi-final.
Fils earlier produced a stunning 6-3 7-6(9) win over Canadian ninth seed Felix Auger-Aliassime, saving five set points and rallying from 0-5 down in the second-set tiebreak to book a place in the quarter-finals for the second consecutive year.
