World number one Novak Djokovic had to recover from dropping the first set as he began the defence of his Indian Wells title with a 2-6 6-1 6-2 win over American Bjorn Fratangelo.
Aiming for a third straight BNP Paribas Open crown, the Serb rallied from losing the first four games to beat the world 149 and reach the third round.
Rafael Nadal also lost a set before beating Gilles Muller 6-2 2-6 6-4.
Serena Williams earned a 7-6 (7-2) 6-0 third-round win over Yulia Putintseva.
The 34-year-old top seed needed 50 minutes to take the opener on a tie-break against Kazakhstan's world number 56, who twice served for the set.
But the second set took only 25 minutes as Williams sealed the match with her seventh ace of the contest.
Defending champion Simona Halep saw off Ekaterina Makarova 6-2 6-4.
Victory for Djokovic, who lost the first four games against qualifier Fratangelo, extended his winning streak at Indian Wells to 12 matches.
"He came out with a good game plan," Djokovic told the ATP's official website.
"I started awful. I think the fifth game in the third was the deciding one.
"That break obviously meant that I can start to feel a bit more comfortable."