The video footage shows the Aussie actor punching the victim in the head while Hemsworth's friend holds the victim down. The victim was clinging to Hemsworth's leg at the time.
Police showed up after the few punches were thrown, dispersing the fight and onlookers.
Hemsworth, who most recently starred in "The Hunger Games", is engaged to singer/actress Miley Cyrus. He's currently shooting Aussie director Robert Luketic's film "Paranoia" in Philadelphia alongside Harrison Ford.Related Video: How Liam proposed to Miley