The fifth seed looked more comfortable in her second match of the season on clay as she brushed aside Marina Erakovic of New Zealand 6-2 6-2.

Serving six aces and winning 80 per cent of her first serve points, the 2008 Roland Garros champion also displayed some impressive groundstrokes to set up a possible semi-final clash with sister Venus.

"I love the clay. I'm always ready to win the French Open," she said. "And I never do. Paris is my favourite city in the world. I hate leaving there."

Venus, playing on a wildcard invitation as she tries to rebuild her ranking following a lengthy lay-off through injury and illness, beat Australia's Anastasia Rodionova 7-5 6-2.

However, a last four meeting of the Americans is far from certain with Serena facing the winner of Germany's Sabine Lisicki or Kazakh Yaroslava Shvedova and Venus due to take on either second-seeded Samantha Stosur or Yaroslava's countrywoman Galina Voskoboeva.