Martina Hingis hardly needed to break into a sweat to overcome Russia's Tatiana Panova in Sunday's fourth round encounter at the Masters Series tournament in Key Biscayne.
The Swiss world number one beat Panova 6-1, 6-0.
Hingis, who has dropped just five games since the start of the tournament, will now face Spain's Magui Serna, currently ranked 27th in the world.
Hingis's first real opposition is likely to come in the quarter-finals, though, where she is expected to meet either Germany's Anke Huber or Nathalie Tauziat of France.
swissinfo with agencies