World number one Caroline Wozniacki eased through her first match in the Family Circle Cup in Charleston with a 6-1 6-1 demolition of Irina Falconi.
Wozniacki, 20, took a 5-0 lead before rattling off six unanswered games to seal her American opponent's fate.
"I'm feeling good on clay, so it's exciting," said Wozniacki.
Second seed Samantha Stosur followed Wozniacki into the third round with a 6-1 6-2 victory over Germany's Patricia Mayr-Achleitner.
French fourth seed Marion Bartoli made an early exit, beaten 6-2 6-3 by 2009 Charleston champion Sabine Lisicki of Germany.
Maria Kirilenko, seeded ninth, fell victim to Anna Tatishvili as the Georgian qualifier recovered from the loss of the first set to triumph 5-7 7-5 6-3.
Wozniacki was forced to retire during last year's semi-final match against Russia's Vera Zvonareva when she hurt her ankle sliding on the green clay court.
"You think about it sometimes a little bit, especially when you go after drop shots," said the Dane.
"But on the other hand, this is a tournament that I've always enjoyed playing and centre court is so cosy."
Wozniacki, winner of titles this year in Dubai and Indian Wells, encountered little resistance from the 128th-ranked Falconi, who had never before faced a number one player.
"She was playing good, but I felt like I could put that extra step into the ball," added Wozniacki. "I made winners on the right chances."
World number five Stosur said her status as defending champion had given her a boost.
"I think it definitely lifts your shoulders up a little bit and puts a smile on your face," said the Australian.
World number eight Jelena Jankovic, the third seed and winner in 2007, also advanced, beating Austrian Tamira Paszek 6-2 6-3.
Russia's Nadia Petrova and Slovakia's Daniela Hantuchova, seventh and 10th seeds respectively, also cruised through without any trouble.
Petrova saw off Romania Edina Gallovits 6-1 6-1, while Hantuchova eased past Evgeniya Rodina of Russia 6-0 6-1.