The eventual victors started the game the brighter of the two teams despite playing against the breeze in the opening period.
However, JK Brackens Óg bounced back, getting a goal through Shane Doyle in the 12th minute.
By the break the Mid Tipp side led 1-4 to 0-6.
St Mary's began the second half strongly and goals from Gavin Ryan and Man of the Match Niall Hoctor put them in a very strong position.
Brackens weren't finished, though, and got another goal of their own through Denis Russell.
The South Tipp outfit weren't phased by this and got a number of late points saw them claim the Sean Treacy Cup again.
