Twice former champion Amelie Mauresmo was knocked out of the Italian Open in the first round on Sunday when she suffered a 4-6, 7-6, 6-2 defeat to Spain's Maria Jose Martinez Sanchez.
France's Mauresmo, ranked 21, edged a tight first set, but lost the second in a tiebreak after she had clawed back two breaks of serve.
She slumped to 5-0 in the decider and pulled back two games before losing serve again, going out when her attempt to recover a sweet drop volley went into the net.
In the second round, Martinez Sanchez will meet Mauresmo's 11th seeded compatriot Marion Bartoli, who beat China's Peng Shuai 6-0, 7-6.
The other seed in action on Sunday, Estonia's Kaia Kanepi (16th) moved into the next round with a 6-4, 6-3 win over American qualifier Vania King.
Fourth seed Venus Williams, who has a bye to the second round along with the other top seeds, will meet Lucie Safarova on Monday after the Czech beat Ukraine's Mariya Koryttseva 7-6, 6-2.
Her second ranked sister Serena will be up against Swiss Patty Schnyder, who tamed the challenge of Colombian qualifier Mariana Duque Marino to go through with a 7-6, 6-3 win.