Cameron Norrie and Katie Boulter both came from a set down to book their places in the third round of the BNP Paribas Open, but men’s top seed Alexander Zverev is already out.
Norrie, who won the title at Indian Wells in 2021, beat Czech 23rd seed Jiri Lehecka 3-6 6-4 7-5.
Dominant first serves provided precious few openings in the first two sets, Lehecka claiming the only break in the opener.
Norrie took his first break opportunity to level and saved a number of break points before taking his chance to seal a place in the last 32.
He will face 10th seed Tommy Paul, who dispatched his fellow American Tristan Boyer 6-3 6-1.
In the women’s draw, 25th seed Boulter saw off Romania’s Irina-Camelia Begu 6-7 6-3 6-0.
Both players grabbed a break of serve in the opening set, Begu seizing the initiative to win the tie break for the loss of just two points.
But Boulter, playing her first match since the Australia Open because of a foot injury, hit back to level and powered to victory in the deciding set.
The British number one will face seventh seed Elena Rybakina after the former Wimbledon champion beat Suzan Lamens 6-3 6-3.
Number two seed Iga Swiatek needed just 61 minutes to beat France’s Caroline Garcia 6-2 6-0, while fourth seed Jessica Pegula eased past Magda Linette 6-4 6-2.
Men’s top seed Zverev admitted he was “playing terribly” after losing to Dutchman Tallon Griekspoor 4-6 7-6 7-6.
Griekspoor needed six match points before completing the victory in more than three hours.
Zverev has struggled with his form since losing to world number one Jannik Sinner in the Australian Open final in January.
"I'm just not playing good tennis at the moment. It's as simple as that," he told reporters.
"I'm not playing a level that I want to play, definitely not playing anywhere near what I played in Australia. I'm just disappointed with my game."
The world number two said he would need to go back to the drawing board. "Right now it's not clicking. I have to find a way to make that happen."
Fourth seed Casper Ruud also went out, losing 7-6 3-6 6-2 to American Marcos Giron.
Eighth seed Stefanos Tsitsipas beat Thiago Seyboth Wild 6-2 6-4 to set up a clash with former Wimbledon finalist Matteo Berrettini, a 6-2 7-6 winner over Australian Chris O’Connell, while 12th seed Holger Rune beat Corentin Moutet 6-2 6-4.
