Italian Open: Simona Halep holds top ranking as Madison Keys withdraws in Rome

Romanian Simona Halep will extend her stay as world number one after being handed a walkover into the Italian Open quarter-finals when American Madison Keys withdrew injured on Thursday.

Halep needed to reach at least the quarter-finals and go further than world number two Caroline Wozniacki to retain the top-ranking going into the French Open. Keys, runner-up in Rome in 2016, was unable to take to court because of a right rib injury.

"I felt my rib in my match yesterday and after trying to warm up this morning it was still painful," she said. Halep, runner-up last year, will play either Sloane Stephens or Caroline Garcia in the last eight.

Cornet pulls out of Strasbourg

Meanwhile, France's Alize Cornet has pulled out of the Strasbourg International tournament because of a groin injury but hopes to be ready for the French Open.

Cornet, who was cleared of an anti-doping violation on Tuesday after a charge against her for missing three out-of-competition drug tests was dismissed, picked up the injury last week in Madrid, where she was beaten in the first round by Elina Svitolina.

"I am very disappointed that I cannot take part in the Strasbourg tournament but unfortunately I have not fully recovered from an adductor muscle injury," the world number 32 said on Twitter on Thursday. "I am going to do everything to be ready for the French Open."

Cornet, who won the Strasbourg tournament in 2013, reached the last 16 at Roland Garros last year. The French Open runs from May 27-June 10.