Top seed Maria Sharapova began her bid to claim the world number one spot with a 6-4, 6-2 win over Anabel Medina Garrigues at the Rome Masters on Tuesday.
Her win came on a mixed day for the Russian contingent. Fifth seed Svetlana Kuznetsova slumped 6-2, 6-4 to Argentina's Paola Suarez and number 11 Elena Likhovtseva lost 6-1, 6-3 to Israel's Anna Smashnova.
Sharapova will replace Lindsay Davenport at the top of the rankings if she triumphs in the Italian capital this week.
It is a tall order for the Wimbledon champion, who has often struggled to produce her best form on clay and only reached two quarter-finals in her previous six tournaments on the surface.
Having received a bye into the second round, she faced a dangerous opponent in slow-court specialist Medina Garrigues.
"Overall I don't think I played great tennis," Sharapova said.
"I hit a lot of errors early on, but first-round matches are never easy, especially against a player like Medina Garrigues, who gets everything back.
"I'm just happy to have won it."
The players twice traded early breaks of serve before Medina Garrigues mis-hit a forehand off the frame of her racket to give Sharapova the break she needed to take the first set.
Sharapova then grabbed a decisive lead in the second set when she whipped a forehand crosscourt winner past the Spaniard to break in the sixth game.
Reigning U.S. Open champion Kuznetsova never really found her range or rhythm as she fell to doubles specialist Suarez in the second round.
Her opponent had only won one of her five singles matches this year, but played solidly from the baseline and took advantage of a string of unforced errors by the Russian.
French 12th seed Tatiana Golovin fell at the first hurdle, beaten 6-3, 6-4 by Ana Ivanovic of Serbia & Montenegro.