Heat starter Ben Moore continued the good work of Trevor Caughey from game two and pitched the whole nine innings for Perth, conceding only four hits and just one run.
Perth's bats also ran hot as they batted in seven runs from eight hits.
Robbie Widlansky recorded two hits for the Heat including a two run homer in the eighth inning.
Neither offense able to score in the first four innings before the Heat's offense exploded in the fifth inning when they scored three runs.
Ronnie Welty singled and Matt Kennelly walked before a Lachlan Dale ground out advanced the runners into scoring position where a Mitch Graham double could drive both of them in.
Tim Kennelly then singled up the middle to score Graham and complete the three run inning.
The Heat then broke Adelaide's spirit in the eighth inning when they drove in another four runs to make the lead a near impossible seven runs with just one inning left.
Adelaide hitter Stefan Welch hit a home run in the top of the ninth to save some credibility for the visitors.
But Moore was able to claim the remaining three outs without being taken out of the game and clinch the ABL Championship Series for the Perth Heat.
The Heat have now won two of the last three national title's including the 2008/09 title and now the inaugural ABL Championship.