South Whyalla beat the more fancied Weeroona Bay in the reserves grand final on Saturday, taking home the team's first premiership since 1991.

It was a tense dour struggle all game, with the scores close until South broke away.

The Demons kicked three goals in the third quarter, adding another three in the last to race away to a handy lead.

This was until the Bays got a couple of late goals to reduce the final margin, but after half time, were never in the race.

The Bays' four-pronged attack of Jason Rae, Geoff Jones, Adrian Jones and Jason Verhaaf never got into the game.

The solid Demon defence held sway for most of the match, until late in the game when it was all over for the Bays.

The experienced South players of Eddie Wilson, Bradley Page, Mark Phillips, Gavin Jonker and Matt Perry were all solid contributors, while Ryan Perry, Shaun McDonald and Greg Havers were others to play well.

The main goal scorers were Havers and Graham O'Brien, who both finished the game with three apiece.

For the Bays, Jason Rae kicked three goals, with Adam Kinnear, Rae, Byron Ferguson, Adam Collins and Rowan Mitchell all playing their part.

Overall it was a disappointing end to the season for the minor premiers, with South's Eddie Wilson winning the medal for best on ground.