Leander Paes and Radek Stepanek have entered the quarterfinals of the men's doubles event at the US Open tennis. Paes and his Czech partner defeated veteran French pair of Michael Llodra and Nicolas Mahut 7-5, 4-6, 6-3 in New York yesterday.Sania Mirza and China's Jie Zheng booked a berth in the quarterfinals of women's doubles event. They beat Anna-Lena Groenefeld of Germany and Kveta Peschke of Czech Republic 6-2, 6-3 in one hour and 12 minutes.India's Divij Sharan and his Taipei partner Yen-Hsun Lu defeated the Israeli team of Jonathan Erlich and Andy Ram 6-4, 5-7, 7-6 in a hard-fought contest.