Madrid Open: Serena sweeps past Sharapova into semis

Serena Williams blew away fellow former number one Maria Sharapova 6-1, 6-3 to join top seed Victoria Azarenka in the semi-finals at the Madrid Open on Friday.

The American ninth seed extended her winning streak over the Russian World No. 2 to seven in a row and to eight from 10 meetings, since they first clashed in Miami back in 2004.

Williams, unbeaten on clay this season, battered down 11 aces, including one on a second serve at break-point in the seventh game of the second set, which seemed to end any hopes Sharapova may have had of coming back into the match.

She will meet either fifth-seed Samantha Stosur or Czech qualifier Lucie Hradecka in the semi-finals.

World No. 1 Azarenka was made to battle hard to overcome Roland Garros champion Li Na 3-6, 6-3, 6-3.

The Belarussian, runner up in Madrid last year, looked to be cruising at 4-1 up in the third before China's Li broke back.

Li was unable to take advantage of four break-point chances, however, and 36 unforced errors told its own story.

Photograph: Jasper Juinen / Getty Images