NEW YORK -- Wang Xiyu shocked world No 3 Maria Sakkari of Greece 3-6, 7-5, 7-5 while Zhang Shuai beat Slovak Anna Karolina Schmiedlova in straight sets as both Chinese players stormed into the women's singles round of 32 at the US Open on Wednesday.

Wang, 21, who lost the first set 6-3 to last year's semifinalist Sakkari, remained calm to keep the 27-year-old third seed at bay with her big groundstrokes.

"I'm excited about the result. Today I did a good job but still need to improve my serving and my consistency. I'm just trying my best to save every ball," Wang said.

The world No 75 took both the second and third sets 7-5 to conclude the match in two hours and 44 minutes and advance to the third round. It was the first time Chinese youngster Wang reached the round of 32 at a Grand Slam tournament.

Zhang, 33, displayed her consistency in the match of one hour and 27 minutes, seeing off the world No 115 player 7-5 and 6-1.

"I played really well today. Passing such a big test let me see my improvement. So happy to see many Chinese men and women youngsters make breakthrough in this tournament," Zhang said.

The world No 36 Zhang reached the singles last 32 at the US Open for the fourth time, with her best results at the Grand Slam events being two quarterfinal finishes at the Australian Open and Wimbledon.

Chinese pair Wang Xinyu and Zhu Lin lost their opening match to Anna Bondar of Hungary and Greet Minnen of Belgium 5-7, 6-3, 4-6 in the women's doubles.