INDIAN WELLS - Reigning Grand Slam champions Aryna Sabalenka and Coco Gauff reached the fourth round of the ATP-WTA Indian Wells Masters on Monday with challenging straight-set wins.
But former number one and 2018 tournament winner Naomi Osaka failed to join them, with the Japanese player eliminated 7-5, 6-4 by Elise Mertens, who now takes on Gauff.
The Belgian saved three break points in the final game, advancing on her second match point which drew an Osaka error.
Osaka, a four-time winner at the majors, is making her return to tennis this season after giving birth.
Earlier, double Australian Open trophy-holder Sabalenka defeated Emma Raducanu 6-3, 7-5 but double-faulted on a match point and needed three more winning chances before finally going through.
The 2023 runner-up to Elena Rybakina here got a tougher-than-expected challenge from 2021 US Open champion Raducanu, who has returned to tournament tennis this year after an eight-month injury layoff.
Gauff, who won the US Open last September as a teenager, overcame Lucia Bronzetti 6-2, 7-6 (7/5) as she closed out victory in a tiebreaker with a minimum of drama.
Sabalenka is playing only her second event since claiming her second trophy at Melbourne Park; she has now won 13 of 15 matches this season.
Raducanu, ranked 250th and playing on a wild card entry, was able to convert on only one of her 10 break chances against the second seed.
Victory in 97 minutes ran Sabalenka's WTA-leading total of Masters 1000 match wins to 82.
"I was super-happy to close this match in two sets; the last game was tight," Sabalenka said.
"It was a key moment. If I had lost that game it would give her emotionally much more belief and confidence - going to the tiebreak you never know, It's 50/50.
"I didn't want that to happen. That's why I felt relief after I closed this match in two sets."