Updated

Rome, Italy (SportsNetwork.com) - Previously red-hot Maria Sharapova lost to a fellow former world No. 1 star, while Australian Open champion Li Na avoided an upset by posting a third-round victory Thursday at the $2.6 million Italian Open.

Eleventh-seeded Serb Ana Ivanovic took down the eighth-seeded two-time Rome champion Sharapova 6-1, 6-4 on Day 4 on the red clay at Foro Italico.

Ivanovic is now 3-8 lifetime against Sharapova, who prevailed in a final in Stuttgart between the two last month. The Russian also topped the Serb in a bout here in Rome two years ago.

Sharapova was seeking her third title in three events, having recently claimed championships in Stuttgart and last week in Madrid. She was a perfect 12-0 on clay this year and 48-3 on the dirt since 2012, with her only losses coming at the hands of Serena Williams, prior to Thursday.

The 27-year-old Sharapova was the back-to-back Rome champion in 2011 and 2012 and lost to Williams in last year's marquee finale in the "Eternal City."

Meanwhile, the second-seeded 2012 Rome runner-up Li eased past former U.S. Open champion, former Roland Garros runner-up and 2011 Rome finalist Samantha Stosur 6-3, 6-1 at this French Open tune-up.

Also on Thursday, third-seeded Polish star Agnieszka Radwanska disappointed the Italian faithful by dismissing former French Open champ Francesca Schiavone 6-4, 6-1, sixth-seeded former No. 1 Jelena Jankovic knocked out 12th-seeded Italian Flavia Pennetta 6-2, 6-3 and 10th-seeded former Roland Garros finalist Sara Errani, of Italy, got past Czech qualifier Petra Cetkovska 6-4, 7-6 (7-3). Jankovic titled here back-to-back in 2007 and 2008 and was the runner-up in 2010.

In a matchup of non-seeds, Chinese Zhang Shuai outlasted American qualifier Christina McHale 6-2, 4-6, 6-2.