Tennis-Azarenka holds off Li to make Madrid semi-finals

World number one Victoria Azarenka was made to battle hard for a semi-final place at the Madrid Open as she eventually overcame Roland Garros champion Li Na 3-6 6-3 6-3 on Friday.

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.

Azarenka will face newly-installed world number three Agnieszka Radwanska or American qualifier Varvara Lepchenkoin the last four.

Former world number ones Serena Williams and second seed Maria Sharapova follow next on centre court. Fifth-seedSamantha Stosur takes on another qualifier Czech Republic's Lucie Hradecka in the other quarter-final.