Sania Mirza quelled a late challenge from world number 49 and 11th seed Anne Keothavong to sail into the pre-quarterfinals of the USD 220,000 WTA Aegon Classic here today.
The unseeded Indian beat the British number one 6-1 7-6 (5) in the second round after battling it out for one hour and 27 minutes.
Sania will now run into the winner of the match between local wild card Elena Baltachs and Russian fifth seed Anastasia Pavlyuchenkova for a place in the last-eight stage.
Sania dominated the first set and did not give any chance to Anee, whom the Indian broke thrice to take lead.
However, Anee shrugged off the rustiness in the second set and put up a brave fight to stretch it to a tie-breaker, where Sania held her nerves and converted her second match point.