China's Wang Xiyu stunned third seed Maria Sakkari at the US Open on Wednesday to reach the third round of a Grand Salm for the first time.

Wang, ranked 75, came from a set down to knock out her Greek opponent, who made the semi-finals last year, 3-6, 7-5, 7-5 in their two-hour 43-minute clash.

The left-hander hit 35 winners and saved 12 of 17 break points and goes on to face either Alison Riske-Amritraj of the United States or Camila Osorio of Colombia for a place in the last 16.

Wang was one of four Chinese women to reach the second round in New York along with Zheng Qinwen, Zhang Shuai and Yuan Yue. (AFP)