The seven-year-old karate fighter recently claimed first in kumite, or fighting, and kata, a set pattern of movements, at the South West Sports Assembly South West Games at Warrnambool.

O'Brien, a prep pupil at St Aloysius Primary School, has been learning karate for two years and has already progressed to a yellow belt.

"I like doing the kicks, but we don't make contact," he said.

"I just wanted to do karate because when I grow up if I got into trouble I wanted to be able to defend myself."

O'Brien said he trained twice a week, and enjoyed the physical activity and learning the different fighting techniques the most.

"I like it because I enjoy it and have made lots of friends and entered tournaments," he said.

Competitors from across the region travelled to be a part of the games.