Champion Lleyton Hewitt began his Pacific Life Open title defence with a 6-2, 6-3 win over Thomas Johansson on Saturday but his fiancee Kim Clijsters withdrew from the women's tournament with a wrist injury.
Second seed Clijsters said she could be off the WTA Tour for up to six weeks nursing a bone bruise and tendonitis in her left wrist.
Winner here last year, the Belgian suffered the injury during her victory over Angelika Roesch on Friday.
Clijsters was not scheduled to play Saturday, but said that she could not grip her racket in practise.
"It's definitely very, very disappointing," the 20-year-old said. "I'm not the youngest player anymore. Maybe playing matches has something to do with it."
Clijsters' compatriot, top seed, Justine Henin-Hardenne eased to a 6-2, 6-2 win in the second round over American Samantha Reeves.
Bulgarian teenager Sesil Karatancheva made the day's biggest splash, when she overcame world number 25 Magui Serna 6-4, 2-6, 7-5.
Karatancheva, at 14 the youngest player in the tournament, recovered from 30-0 down as Spaniard Serna served for the match in the third set.
She plays Russian 16-year-old Maria Sharapova next.
"Yes, I do think I can kick her ass off," Karatancheva said.
Sharapova, who has won two WTA titles, pulled off a 6-3, 4-6, 6-4 victory over Italy's Flavia Pennetta, hitting seven winners while taking the last eight points.
Displaying remarkable consistency from the baseline Hewitt won his 13th straight match at Indian Wells as he attempts to win the title for the third year running.
The Australian's last defeat in the tournament was in the 2001 semi-finals against Andre Agassi, who also progressed to the third round on Saturday with a 6-2, 6-2 win over Spain's David Sanchez.
Mark Philippoussis was one of four seeds to go out of the tournament. The Australian 12th seed lost 7-6, 7-5 to Russia's Mikhail Youzhny.
Wayne Arthurs upset sixth seed Rainer Schuettler 6-1, 7-6. Germany's Tommy Haas continued his comeback from a shoulder injury with a 6-1, 6-2 win over 10th seed Paradorn Srichaphan and American Taylor Dent beat 15th seed Gustavo Kuerten 6-4, 7-5.
