Sania Mirza has entered the quarter-finals of women's singles of Pattaya Open Tennis tournament, in Thailand, defeating Anne Keothavong 6-4 7-5. The unseeded Indian tamed the giant-killing British rival in a hard-fought second round match after one hour and 40 minutes struggle. She will now face either Japanese Kimik Date-Krumm or Chinese Taipei qualifier Su-Wei Hsieh in the quarter-finals.Sania has also reached the women's doubles quarter-finals with Australian partner Anastasia Rodionova. The top-seeded pair routed a hapless French pair of Iryna Bremond and Caroline 6-0 6-2 in the first round.They are now up against local pair of Varatchaya and Varunya Wongteanchai in the last-eight stage match.