Serena Williams has said that she was relieved to overcome the challenge of Sorana Cirstea in Sunday's Rogers Cup final.

Romanian Cirstea, 23, had beaten Caroline Wozniacki, Jelena Jankovic, Petra Kvitova and Li Na earlier in the Toronto tournament, but she fell at the last hurdle as Williams prevailed 6-2 6-0.

Williams admits that she was pleased to avoid joining her fellow seeds on Cirstea's list of victims.

"I know she's so capable of winning big matches," Williams told reporters. "And she's had so many big upsets this week. I didn't want to be another casualty."

Williams has now won the Rogers Cup on three occasions.