Serena Williams bowed out of the Indian Wells Open due to illness, while Simona Halep and Elina Svitolina enjoyed strong wins.
Williams, a two-time champion of the event, trailed Garbine Muguruza before retiring due to a viral illness.
Halep and Svitolina were impressive in third-round victories on Sunday, while Ashleigh Barty also progressed.
However, there was no such luck for the likes of Johanna Konta and Jelena Ostapenko.
SERENA DEPARTS IN CALIFORNIA
Williams trailed fellow seed Muguruza 6-3 1-0 when the 23-time grand slam champion retired.
Despite initially complaining of a leg injury, Williams' retirement was officially due to a viral illness.
The result saw Muguruza set up a fourth-round meeting with Kiki Bertens, the seventh seed who overcame Konta 7-6 (12-10) 6-4.
HALEP, SVITOLINA AND BARTY SHINE
Halep, the 2015 champion, was challenged but got past qualifier Kateryna Kozlova 7-6 (7-3) 7-5.
The Romanian was one of six seeds to progress, with Svitolina joining her after a 7-5 6-4 win over Daria Gavrilova.
Barty, the Australian 12th seed, was in fine form as she brushed past wildcard Jennifer Brady 6-3 6-2, setting up a meeting with Svitolina.
OSTAPENKO, MERTENS EXIT
Ostapenko was unable to survive a test from Marketa Vondrousova, who edged to a 4-6 6-3 6-4 win.
Along with Williams, the other seed to depart was Elise Mertens, the Belgian beaten by Wang Qiang 7-6 (7-4) 6-7 (4-7) 6-3 after a three-hour battle.