They trailed by five points with a quarter of an hour to go.
Laois secured a All Ireland Intermediate Camogie semi-final birth against Antrim next weekend.
A stunning comeback win over Kerry, in which they only managed one score in the opening 45 minutes accounted for that.
The kingdom led by 1-5 to 1-0 with fifteen minutes remaining in the contest, a solitary Sara Cuddy goal the only mark on the scoreboard for the O'Moore women.
However John Desmond's side showed great heart in terrible conditions, tagging on five points without reply in the closing stages to force extra-time.
Two Clodagh Tynan points in injury time proving crucial.
They took control in the additional time, Kirsten Keenan was immaculate from frees throughout the day, top scoring with four points.
Laois dominated, going on a five points to one run to leave the scoreline 1-10 to 1-6 in their favour after the extra period.
Third Time The Charm As Laois Claim Joe McDonagh Cup
Offaly Pupils Become Local Stars After Publishing Bestselling Book
Katie Taylor To Fight At Croke Park In September
Laois And Westmeath Set For Big Tests In Intermediate Camogie Championship
I Knew I Had To Play A Good Round To Win - Ella Cantwell
Mullingar Athletic And Clonaslee United To Clash In Combined Counties Cup Final
Shane Lowry And Rory McIlroy In Contention At Memorial Tournament
There's Serious Competition In The Laois Panel - Mark Dowling
Westmeath Ladies Look To Book All-Ireland Quarter-Final Spot
Alex Dunne Aiming For Big Weekend In Monaco
Offaly Camogie Captain Looking Forward To Kilkenny Clash
Shane Lowry In Action At Memorial Tournament
Laois Aiming To Make It Third Time Lucky In Joe McDonagh Cup Decider
Galway To Host Westmeath On Sunday June 14th
Second Round Draw Made For FAI Cup
Cian Reddy Keeps Up Unbeaten Professional Record
Westmeath Ladies Get Opening Win In All-Ireland Intermediate Championship
Athlone Town Knocked Out Of All-Island Cup
Limerick See Off Offaly In Senior Camogie Championship
Athlone Town Suffer Defeat Away To UCD In First Division