Second seed Sania Mirza overcame a second-set hiccup to advance into the quarter-final of the US $175,000 Japan Open Tier III WTA event in Tokyo on Wednesday.
The Indian ace beat Australia's Casey Dell'Acqua 6-4, 3-6, 6-4 in the second round.
On Tuesday, Sania had also advanced to the quarter-final of doubles, as she and her American partner Christina Fusano notched a 6-3, 6-2 win over Polish-Romanian pair of Ursula Radwansaka and Agnes Szatmari.
Sania will face the winner of the match between Flavia Pennetta and Abigail Spears in the last eight.