WASHINGTON, March 10 (Xinhua) -- Chinese number one Wang Qiang was made to work hard before defeating Elise Mertens of Belgium 7-6(4), 6-7(4), 6-3 in the third round of the BNP Paribas Open women's singles event on Sunday.

Wang, seeded 18th in the tournament, needed almost three hours to withstand Mertens' challenge and will take on Bianca Andreescu of Canada in the round of 16.

With this victory, Wang also improved her head-to-head record against Mertens to 3-0.