China's Li Na returns the ball to Serbia's Jelena Jankovic during their match at the Italian Open tennis tournament in Rome, May 16, 2013. [Photo/icpress.cn]

In the women's draw, world No 1 Serena Williams routed 14th-seeded Dominika Cibulkova 6-0, 6-1 for her 21st consecutive win, matching the best streak of her career.

As local hope Sara Errani of Italy was playing in the main stadium, Williams was arranged to play on an outer court. She didn't make the appearance last too long, winning in 61 minutes.

The second seed Maria Sharapova also won easily as she beat 16th-seeded Sloane Stephens 6-2, 6-1.

No 3-seeded Victoria Azarenka was up 6-1, 2-0 when Ayumi Morita retired. Azarenka won 70 percent of the points in the match when play stopped.

Those top three seeds were joined in the quarterfinals by two-time champion Jelena Jankovic, who edged fifth-seeded Li Na of China, 7-6 (2), 7-5.

The last remaining Italian in the tournament is Errani, who advanced when 12th-seeded Maria Kirilenko of Russia retired while trailing 6-3, 2-0 with a left knee injury.