Former world No 1 Caroline Wozniacki made an early exit from the Italian Open after losing a marathon match to Bojana Jovanovski, 2-6 6-4 7-6 (7/5).
The 10th seed is still without a win in a major clay-court tournament this season with the French Open just two weeks away.
Denmark's Wozniacki laboured for almost three hours in a struggle which ended in front of a standing-room only crowd, eventually falling to her 48th-ranked opponent in a third-set tie-break.
Wozniacki had beaten the 21-year-old from Belgrade in both of their previous meetings, but was burdened with six double faults while losing serve seven times.
With her victory, the Serb ended a poor run of form and claimed her first win since mid-January at the Australian Open.
Roberta Vinci restored order for the seeds at the Foro Italico as 13th-seeded home favourite came through her contest against Elena Vesnina from Russia, despite losing the opening set on a tie-break 6-7 (2/7) 7-5 6-4.
But it wasn't such good news for another Italian, Karin Knapp who lost 7-5 6-2 to young American Christina McHale.
The world No 12 Maria Kirilenko beat Spain's Anabel Medina Garrigues 6-3 6-3 while 14th-seeded Dominika Cibulkova from Slovakia overcame France's Kristina Mladenovic, 1-6 6-2 6-2.
Meanwhile, German Julia Goerges had a scare against Czech Andrea Hlavackova after losing the opening set before advancing.
In the second round, left-handed eighth-seed Petra Kvitova showed good form to beat big-serving Sabine Lisicki in three sets, 6-4 0-6 7-5.
Madrid semi-finalist Ana Ivanovic lost 6-3 2-6 6-2 to Urszula Radwanska but Sloane Stephens got the better of Flavia Pennetta, the 6-3 6-3 triumph ending a barren run of results for the American.