World No.2 Li Na came from a set down to beat 16th seed Sloane Stephens on Thursday to reach the quarter-finals of the Madrid Open tennis tournament.

The Australian Open champion had no answer to American Stephens’s power initially as the Chinese star dropped her first set of the week.

However, Li fought back to win 2-6 6-3 6-2 and set up a meeting with four-time grand slam champion Maria Sharapova or Australian Sam Stosur in the last eight.

Czech fifth seed Petra Kvitova also advanced to the quarter-finals with a 6-4 6-3 win over countrywoman Lucie Safarova.