A dominant bowling performance set up the win for the top side, which last month clinched the Twenty20 Cup and has now won its second first-grade title in four years.
Tea Tree Gully rolled the young Sturt side for only 103, secured the first innings win for the loss of four wickets and by stumps on Saturday was 93 runs ahead with four wickets remaining.
The lead stretched to 213 runs on Sunday and Sturt was 5/73 in its second innings when it accepted an outright win was out of reach.
Opening bowler Ben Atkinson won the David Hookes Medal after sparking Sturt’s first day collapse with two wickets in his first two overs and finishing with 3/26 from 13.5 overs.
He dismissed Jacob Dick second ball and then - after Ben Hutchinson removed Connor Dudley the next over – snared the important wicket of Sturt captain Brad Davis.
Sturt slumped to 7/57 before Alex Gregory and Ulricht van Duyker both made 26 to push the total to 103.
Adam Somerfield (3/16), Hutchinson (2/33) and Brad Evans (1/10) completed the demolition in 46.5 overs.
Tea Tree Gully also lost an opener on the second ball of its innings, Kosta Sinodinos removing Jack Holliday for a duck.
Patrick Page jnr (40), Tim Evans (15) and semi-final hero Joe Gatting (7) were back in the rooms with 30 runs still required but Travis Head (35) and Tim Davey (76) steered their side into the lead, Davey smashing seven sixes in his 57-ball knock.
Tea Tree Gully’s handy tail extended the lead to a title-sealing 213 runs on Sunday, Brad Evans finishing unbeaten on 66.