Castletown Geoghegan had looked in control just moments from time.
Clonkill are Slevin Coaches Westmeath Senior Hurling champions for a record 17th time.
Pat O'Toole's side secured their third successive crown by defeating Castletown Geoghegan by 3-16 to 2-16 after extra time in Mullingar yesterday.
Castletown had been on course for victory but a goal three minutes into injury time from Jordy Smyth sent the game into extra-time.
Niall Mitchell, who was returning from a shoulder injury, also netted in extra-time to secure a three-point victory for the men in green and gold.
Clonkill captain Brendan Murtagh became the first player to ever lift the Westmeath Examiner Cup three times as skipper and he says it was a special moment:
Their manager Pat O'Toole spoke with Gerry Russell after the game:
NHL: Offaly Face Limerick In Final League Game
Portlaoise Panthers Looking To Continue Good Form In Division One
Shane Lowry In Action In Florida This Week
NHL: Improving Each Week The Goal For Laois
Grainne Walsh Progresses At Strandja Memorial Tournament
Crunch Weekend For Midlands Sides In National Camogie League
James Gormley Named On Irish Squad For FIBA EuroBasket Qualifiers
Portlaoise Panthers Suffer Tough Defeat In Super League
CCFL: St Peter's Extend Their Advantage At Top Of Premier Division
NFL: Relegation Firmly On The Cards For Offaly
Laois "Devastated" By Defeat Despite Delivering "Manliness" - Justin McNulty
Westmeath Ladies Bag First Win Of League Season
Big Camogie Wins for Westmeath and Laois Over The Weekend
Fitzgerald "Relieved" After Squeaking Past Kerry
NHL: Galway Prove Too Strong For Offaly
Former Laois And Offaly GAA Manager Honoured By An Garda Síochána
Athlone Town Make It Two Wins From Two In First Division
Lee Fitzpatrick Scores Try For Ireland U20s In England
NFL: Westmeath Move Closer To Promotion
Shane Lowry Finishes Strong In California