Early exit for Serena

The American, who won the title in Paris in 2002, made error after error as she fell 6-4 6-4 to the 27th seed on Suzanne Lenglen court.

Srebotnik, from Slovenia, clinched the victory on her third match point when Williams, who cut a frustrated figure for much of the 90-minute contest, sent a forehand wide.

It is Williams' earliest exit from Roland Garros since 1999, when she also lost in the third round.

Meanwhile, second seed Ana Ivanovic defeated Caroline Wozniacki in a second successive grand slam event to progress through to the fourth round.

The Serbian was pushed hard by the promising 17-year-old from Denmark in a pulsating first set but eventually eased to a 6-4 6-1 win on Philippe Chatrier court.

Ivanovic, a winner against Wozniacki in the fourth round of this year's Australian Open, will next play Petra Cetkovska, who beat fellow Czech Iveta Benesova in straight sets on Court Two.

In another second-round match, top seed Maria Sharapova needed three sets before seeing off Bethanie Mattek on Philippe Chatrier court.

The Russian was a set up when her match was suspended on Thursday evening due to bad light. Resuming 3-2 down in the second set, she lost her way and allowed Mattek to take it to a decider but Sharapova won out 6-2 3-6 6-2.

The new world number one will meet Italy's Karin Knapp, the 32nd seed, in the third round.