P – Francesca Schiavone, the 2010 French Open champion, was knocked out of Roland Garros in the third round on Saturday, losing in three tight sets to unseeded American Varvara Lepchenko.
Lepchenko, with an upset 3-6 6-3 8-6 win, will tackle fellow left-hander Petra Kvitova, the fourth seeded Czech, for a place in the quarter-finals.
Kvitova had earlier needed three sets to beat Russian world No.109 Nina Bratchikova to reach the last 16.
The Wimbledon champion won 6-2 4-6 6-1.
The 63rd-ranked Lepchenko had never made it beyond the second round at any grand slam tournament.
She joins Sloane Stephens, who won on Friday, to give the United States two unseeded women in the fourth round at a major tournament for the first time since Wimbledon in 2002.
Lepchenko was born in Uzbekistan and lives in Pennsylvania after becoming an American citizen last year.
In the men’s, Spain’s David Ferrer reached the last 16 with a 6-0 6-2 6-2 demolition of Mikhail Youzhny of Russia.
The sixth seed will play Frenchman Paul-Henri Mathieu or fellow Spaniard Marcel Granollers for a place in the quarter-finals.