The professional skateboarder and Jackass star was staying in Adelaide at the weekend, while touring the country with his brother Jess's band CKY for the Soundwave festival.
Margera was walking down the street with a woman when they were approached by her ex-boyfriend, "an unidentified, unbeaten professional featherweight boxer", according to TMZ.
The website claimed that the two men exchanged a few heated words before the fight broke out, but one onlooker said that Margera "held his own" and "didn't get hurt that bad".
The police were allegedly called to the incident, but no arrests were made.
Last time Margera visited Australia, he told the Herald Sun that he lost consciousness and ended up "stranded" in Melbourne because someone had spiked his drink.
He was arrested at the New Orleans Mardi Gras last month for swimming with his clothes on and was caught up in a street brawl with a taxi driver in New York last year.
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