A US stand-up comedian who performed a racist impression of an Asian property developer has been attacked by a man of Asian ethnicity sitting in the front row.

Video of the performance shows New York comedian Brett Eidman struggling to raise even a few laughs from his audience before he changes tack and introduces a stereotypical Asian character called Dom Fuk.

The stunt fails to change the mood of the small crowd, who only seemed to laugh out of politeness as Eidman speaks in a stereotypically Asian manner while wearing a pair of glasses that make his eyes appear narrow.

Eidman carries on the performance despite the obvious discomfort of an Asian couple sitting in the front row.

When Eidman suggests the woman should leave her boyfriend and then quotes some classic lines from Stanley Kubrick's Vietnam war film Full Metal Jacket, her Asian partner, who identifies himself as George, finally loses his temper.

Livid, George leaps onto the stage and appears to throw a punch at Eidman just as he delivers the line “me so horny” and thrusts his pelvis. George continues to rain blows down on Eidman until he is dragged away.

Eidman has defended his performance on Twitter, saying he did not do anything to provoke the attack, but adding that he planned to retire the Dom Fuk character.

"I will heal and regroup and hit the stage again soon," he wrote.

"I'm just glad this ass wipe didn't have a gun."

Online commentators have suggested the stunt may have been staged, pointing out that the punch did not connect. Viewers have also questioned why a small, low-profile comedy show such as Eidman’s would have had two people filming in the audience from different angles.