The son of former South Melbourne centre half forward Jim Gull, Stewart played in the same position as his father.
Gull, after being recruited from North Ballarat, kicked three goals on his league debut, against Hawthorn at Lake Oval.
He had his most prolific season in 1976 when he booted 36 goals, which was bettered only by Robert Dean from his club, with 37.
Two years later, in a high scoring game against Geelong, Gull kicked eight goals but finished on the losing team despite South Melbourne amassing 155 points.
When he crossed to Melbourne in 1979, he could only manage two appearances before breaking his collarbone against a goal post, which prompted his retirement.