Sania came through 6-4 3-6 6-4 after a few nervous moments in her second-round match of the tier III event.

After splitting the first two sets, Sania and Dellacqua played out an engrossing decider in which the Indian ace came out trumps to advance to the last-eight.

However, the world number 29 Sania had to stave off stiff resistance from the 84th-ranked Australian in the final set.

The 20-year-old Hyderabadi rallied from being two service breaks down -- in the first and fifth game -- to go 4-3 up with a couple of fiery aces.

Dellacqua held her serve to make it 4-4 but lost the plot from there on and was broken in the 10th game as Sania clinched the contest after the Australian hit a forehand out.

Sania said her experience of playing at the top helped her turn the tide in her favour in the tense battle.

"It's about making those points when it really counts. Probably she didn't make them the whole match, but I made them at 4-4 and I made them at 5-4. I think that counted at the end," she said.