Serena Williams is on the longest winning streak of her career.

The top-ranked American rolled past Spanish opponent Carla Suarez Navarro 6-2, 6-0 Friday to reach the Italian Open semifinals and extend her victory run to 22 matches.

Williams had twice won 21 in a row before, although both of those streaks came a decade ago, in 2002 and 2003.

In the other half of the draw, two-time defending champion Maria Sharapova withdrew before her quarterfinal against seventh-seeded Sara Errani due to illness.

Showing off near-perfect form less than 10 days before the French Open, Williams has dropped just three games in her last two matches. Against the 22nd-ranked Suarez, the American hit winners seemingly at will.

The 15-time Grand Slam winner has also won her previous three tournaments.

Williams will next face either two-time Rome winner Jelena Jankovic or Romanian qualifier Simona Halep, who were playing later on an overcast day at the Foro Italico.

Williams' only title at this clay-court tournament came in 2002, when she beat Justine Henin in the final. That was also the year she won her only French Open title. Last year in Paris, Williams suffered her first ever opening-round loss in a major, falling to 111th-ranked Virginie Razzano of France.

Sharapova said he was struggling with an illness she first contracted last week, although she showed no problems Thursday as she beat 16th-seeded Sloane Stephens 6-2, 6-1. She was runner-up to Williams in last week's Madrid Open.

"I was already a bit off in Madrid and played though it and it came back last night and I got sick again and it's not smart to compete again," said Sharapova, adding that she had a fever after beating Stephens. "Obviously with the French Open coming up it is important to make smart decisions."

The withdrawal means Errani advances to the semifinals. The Italian's opponent will be either third-seeded Victoria Azarenka or ninth-seeded Sam Stosur.

The last Italian to reach the semifinals in this tournament was Raffaella Reggi, who won the 1985 event, which was held in the southern city of Taranto.

The French Open begins May 26.