There were plenty of highlights as Karolina Pliskova, Garbine Muguruza and Dominika Cibulkova reached the last 16 at the BNP Paribas Open.
Czech third seed Pliskova had no troubles against Irina-Camelia Begu as she triumphed in straight sets at Indian Wells on Sunday.
Muguruza - the seventh seed - was pushed by American youngster Kayla Day in her three-set victory.
Cibulkova faced elimination in the third round but outlasted Kristyna Pliskova in a thriller, while Timea Bacsinszky overcame fellow seed Kiki Bertens in a marathon.
PLISKOVA SHOWS IMPROVEMENT
Having flirted with defeat against Monica Puig on Friday, Pliskova produced an improved performance to down Begu 6-4 7-6 (7-2).
Pliskova tallied 21 winners throughout the match and posted just four unforced errors in the first set.
Awaiting Pliskova in the fourth round is Bacsinszky, who outlasted Bertens.
MUGURUZA OUTLASTS DAY
Reigning French Open champion Muguruza had to dig deep for her 3-6 7-5 6-2 win.
After stunning Australian Open semi-finalist Mirjana Lucic-Baroni, another upset looked on the cards when Day raced out to a 5-1 lead and claimed the opening set.
But Muguruza crucially reeled off five successive points to thwart Day in the decisive fifth game of the second set and the Spaniard never looked back.
Elina Svitolina is next after the 10th seed won her 15th consecutive match, defeating Daria Gavrilova 6-2 6-1.
BACSINSZKY SAVES FOUR MATCH POINTS
It was a clash for the ages as Bacsinszky prevailed 6-3 5-7 7-6 (10-8) over Bertens.
Bacsinszky saved four match points and wasted three of her owns as she won the topsy-turvy three-setter in three hours, 22 minutes.
"Is there a hospital nearby? To be more serious, when you're at 6-6 in the third after a rollercoaster match, you know it can go either way," Bacsinszky told WTA Insider. "There's no right tactics, things to do, thinking you have to hit aces or take more risks. It's all about feeling what's coming, when, how, trying to gauge what your opponent is thinking."
CIBULKOVA COMPLETES COMEBACK
The 2014 Australian Open runner-up somehow won 2-6 7-6 (7-5) 7-6 (7-4).
Kristyna Pliskova was in complete control, up a set and 5-3, but Cibulkova fended off a match point and saved 18 of 23 break points to advance.
Anastasia Pavlyuchenkova, Caroline Garcia and Svetlana Kuznetsova also won through.