Top seeds Novak Djokovic and Serena Williams both fought off underdog opponents on Sunday to advance with third-round wins at the Indian Wells Masters.
Fourth seed Rafael Nadal had to work for more than two hours in distracting wind to finally secure a 6-2, 2-6, 6-4 defeat of Gilles Muller, with the event's billionaire owner Larry Ellison watching proceedings.
Djokovic was taken by surprise in the first set by former junior grand slam winner Bjorn Fratangelo as the American won the opening set before being pegged back 2-6, 6-1, 6-2 by the world number one.
"I must admit that he played really good tennis, especially in the first set. He came out with a good game plan, knowing what to do," Djokovic said. "I started awful.
"I didn't play really great except the second set. It was about just finding a way to win."
It was a similar - if less dramatic - story for Williams, who needed to gain traction, staging a first-set comeback in a 7-6 (7-2), 6-0 victory over Kazakh Yulia Putintseva.
Williams, playing for only the second time in 15 years at an event that she had long boycotted, was cheered to a victory in which she overcame 33 unforced errors, while breaking five times.
The top seed will next play Kateryna Bondarenko, a winner over fellow Ukrainian Lesia Tsurenko 3-6, 6-4, 7-6 (9-7), advancing on her sixth match point against a cramping opponent.
Williams went down a break in the first set but levelled at 5-all. The 21-time grand slam winner was then broken to love before breaking back and taking the set into a winning tiebreaker.
There was no stopping Williams in the second set as she powered to the win.
"I was just trying to find my rhythm out there, trying my best to not get off to a slow start. Then I got broken really early, and I couldn't manage to break back," she said. "I was just trying to fight out there and do what I could."
Williams admitted to struggling but insisted: "I'm tournament ready. I've been playing professional tennis for over 20 years. If I'm not tournament ready now, then I'm never going to be."
Her slow start showed "there is always something I can improve on."
Third seed Agnieszka Radwanska beat tricky Romanian Monica Niculescu 6-2, 6-1, while eighth seeded Czech Petra Kvitova survived a scare before downing Swede Johanna Larsson 6-3, 4-6, 7-5.
In the men's draw, Japan's fifth seed Kei Nishikori started with a defeat of Mikhail Kukushkin 6-3, 6-3.
"It was a pretty good match, not easy for me playing first match of the tournament always. But I felt good rhythm there," he said.
"It's always a little bit windy, especially in the stadium. I was not expecting the perfect match, but it's not easy match against Kukushkin. He hits flat - I had to stay patient."
Seventh seed Jo-Wilfried Tsonga won a battle with fellow Frenchman Vincent Millot 7-5, 6-1, while American ninth seed John Isner put out Andreas Seppi 7-6 (7-1), 6-4. Young Austrian ace Domenic Thiem, seeded 11th, beat Jozef Kovalik 7-6 (7-4), 7-6 (7-3).
Roberto Bautista Agut of Spain, the number 14, got a walkover against Mikhail Youzhny, while 16th seed Gilles Simon won a roller-coaster match with Vasek Pospisil of Canada 1-6, 6-0, 6-1.
German teenager Alexander Zverev continued his upward trajectory in the sport, beating former next-generation hope Grigor Dimitrov 6-4, 3-6, 7-5. Compatriot Philipp Kohlschreiber crushed Denis Kudla 6-0, 6-1 to next face Djokovic.
Adrian Mannarino beat Benoit Paire 6-1. 6-3, Sam Querrey stopped Thiemo de Bakker 7-6 (7-5), 6-4, and Feliciano Lopez defeated Spanish compatriot Guillermo Garcia-Lopez 6-2, 6-2.