Serena Williams won a tough match in her comeback following a six-month layoff, rallying to beat unseeded American Bernarda Pera 4-6, 6-4, 6-1 at the Top Seed Open.
The 23-time Grand Slam champion labored to avoid her 14th loss to an opponent ranked outside the top 50.
Venus Williams had a much easier time against Victoria Azarenka. Now the Williams sisters will meet in the second round.
It will be the 31st time they play each other in a match and for both it figures to be emotionally and physically challenging.