American Coco Gauff hits a return to China's Sun Xinran during their women's singles match at the China Open in Beijing. (AFP pic)

BEIJING: Coco Gauff said she had received an "insane" amount of racial abuse on social media after the two-time Grand Slam champion beat local teenager Sun Xinran at the China Open on Monday in a match where a replayed point sparked an online backlash.

The American won 7-5 6-1 to reach the fourth round, but was targeted after stopping play during a crucial point in the first set, raising her hand to complain about a flickering advertising board just as Sun was about to put away a winner.

After a video review, the umpire ordered the point to be replayed. Gauff won the replayed point and held serve for 5-5 before cruising to victory against the Chinese 16-year-old.