Li Na through at Miami Masters

Li Na has reached the fourth round of the Miami Masters with a straight-sets victory over American Varvara Lepchenko.

The Chinese world number five was ruthless in the opening set as two service breaks saw her take it 6-2 inside 35 minutes.

Lepchenko, seeded 25th, put up more resistance in the second, but former French Open champion Li battled through to close out the match 6-4.

Li will face either ninth seed Caroline Wozniacki or Garbine Muguruza for a place in the quarter-finals.