Maria Sharapova pulls out of Italian Open because of illness

Maria Sharapova's preparations for the French Open suffered a setback after she withdrew from the Italian Open because of illness.

The Russian, who defends her French Open title from 26 May, was due to play Sara Errani in Friday's quarter-finals.

"I'm sorry," Sharapova wrote on Twitter. "Didn't recover after being sick last week and it got me again."

Top seed Serena Williams moved into the semi-finals with a 6-2 6-0 victory over Spain's Carla Suarez Navarro.

It was the American's 22nd victory in a row and means she has overtaken her previous best run of 21 successive wins recorded in 2002 and 2003.

The 15-time Grand Slam winner, who has won her last three tournaments, has only dropped three games in her last two matches as she chases a 51st WTA title.

"I've been pretty consistent, and pretty healthy - knock on wood," Williams said. "I feel great, never felt better."

The world number one will next face Romanian qualifier Simona Halep, who beat former Rome champion Jelena Jankovic 4-6 6-0 7-5.

Italian Errani's opponent will be either third-seeded Victoria Azarenka or ninth-seeded Sam Stosur.

Sharapova has been in good form, reaching the Madrid Open final last week only to be beaten by Williams 6-1 6-4.

The 26-year-old comfortably beat American Sloane Stephens 6-2 6-1 on Thursday to reach the last eight in the Italian capital.