CSI: Crime Scene Investigation star Eric Szmanda is nursing a bruised ego after a large woman beat him up in a bar on Hawaiian island Kauai.

The actor, who plays forensics sleuth Greg Saunders on the hit show, was holidaying with friends recently when they decided to check out a local tiki tavern on the island.

After posing for pictures with fellow holiday makers and locals, Szmanda was leaving the bar when he was confronted by "a big Samoan woman."

He recalls, "I thought she wanted to shake my hand, but she clocked me in the face."

The actor is still none the wiser as to why he became a victim: "Maybe she didn't like my Hollywood kind in her bar."

Hawaiian police detectives are investigating the bar brawl.