St Brigid's battled from eight points down to secure their first ever All-Ireland title with Frankie Dolan's injury-time point securing a 2-11 to 2-10 win at Croke Park.
Goals from Dean Rock and Philly McMahon had Ballymun in the ascendancy but a stunning comeback from Roscommon champions helped them to seal a famous win.
Ted Furman and Senan Kilbride exchanged early points before Ballymun got into their stride and caught St Brigid's on their heels.
Dean Rock got on the end of John Whelan's long ball to flick to the net past Shane Curran for the games opening goal.
Before Brigid's could catch their breath, Kickhams had another goal when Curran produced a great save to keep out Furman's shot but the rebound fell kindly to Philly McMahon who found the net.
Dean Rock and James Burke added further points for the Dublin side before St Brigid's finally got going as Kilbride gathered a long ball and and somehow found the net despite being fouled as he got his shot away.
Both sides exchanged scores before the break with Rock and Furman for Ballymun and Dolan and Mannion for St Brigid's on target as Ballymun led 2-6 to 1-5 at the interval.
Senan Kilbride reduced the gap with a fine fisted effort.
Kilbride and Rock exchanged points before Karol Mannion capitalised on confusion in the Ballymun penalty area to fist to the net and level matters Both sides traded further scores before veteran attacker Frankie Dolan slotted over to put the Roscommon champions 2-10 to 2-9 in front with 15 minutes to go.
Ted Furman and Dean Rock kicked Ballymun's 10th and 11th wides as Ballymun struggled to restore parity.
Jason Whelan drew the sides level before missing a relatively easy free to put Ballymun back in front with five minutes remaining.
Ballymun were left to rue those misses as Frankie Dolan hit a left-footed point in injury-time to secure the win.