The defending champion Russian Nadia Petrova has stormed into the quarterfinals of the US $ 220,000 WTA Bell Challenge after ousting Madison Brengle of America in straight sets on Wednesday.

The top seeded Petrova, who was stunned by US teenager Melanie Oudin in the fourth round of the US Open, defeated Madison by 6-3, 6-2 in the second round in just 69 minutes to move to next round.

Petrova smashed 10 aces in the match to race away with the match against 19 year-old Madison. Petrova had defeated Carly Gullickson of America 6-2, 6-0 in the first round on Tuesday.