The reigning league champions needed a pointed ‘65’ from substitute Niall McMorrow to force a replay in the final seconds of extra-time at O’Connor Park.

The momentum was with Galway after they had cancelled out a 2-15 to 0-18 deficit in the closing stages of normal time, with surprise starter Joe Canning landing three successive points.

It was advantage Galway when the Dubs had Ryan O’Dwyer and Alan McCrabbe sent-off in the first period of extra-time, however Anthony Daly’s men produced a gritty finish to ensure a stalemate.

Canning's inclusion provided the pre-match drama, as it had been expected that his first inter-county appearance would come in the Championship proper.

However, the Portumna clubman, who injured his shoulder in late February, started today at full-forward for the Tribesmen and went on to score 0-12.

He was in match-winning form at times, but it was Dublin who took a 0-9 to 0-7 lead into half-time.

They had their only free-taker supreme in corner forward Paul Ryan who kept the scoreboard ticking over for them. He finished with 0-9 in all.

Damien Hayes posed an early threat for Galway and Dublin goalkeeper Gary Maguire had to react smartly to save stinging shots from Hayes and fellow corner forward David Glennon.

A defence-dominated opening 35 minutes gave way to a more open second period with Conor McCormack and Ross O'Carroll breaking through for Dublin's goals.

McCormack rippled the net shortly after the restart to push the Dubs into a five-point lead. Anthony Cunningham's decision to move Canning out into the half-forward line paid dividends, with the youngster becoming hugely influential as the half wore on.

The Tribesmen enjoyed a purple patch during which they outscored Dublin by 0-7 to 0-1. But their 0-15 to 1-11 lead was a shortlived one, with corner forward O'Carroll blasting home a 57th minute goal to move his side back in front.

It was point for point after that until a late spurt from Daly's charges looked to have won it for them. McMorrow and Johnny McCaffrey had them in sight of the finish line, only for Canning to convert two close-in frees and then tag on a point from play from an acute angle for the levelling score at 2-15 to 0-21.

Extra-time was called for and Canning continued where he left off, slotting two frees as Dublin had O'Dwyer dismissed for an off-the-ball incident.

Cunningham's side seemed in control. But yet another twist was produced when Ger O'Halloran fouled O'Carroll for a penalty. However, much to Dublin's dismay, McCrabbe's penalty effort was deflected wide and he only had the consolation of pointing the resulting '65'.

A late pull by McCrabbe then led to him being sent-off by referee Barry Kelly and the Metropolitans had a real mountain to climb.

They were clinging onto their Division 1A status when Cyril Donnellan added to Galway's lead which stood at 0-24 to 2-16 after the first period of extra-time.

But a determined final push saw them live to fight another day. After an even start to the second period, the Dubs dug deep to land the closing points from substitutes Daire Plunkett and McMorrow.

DUBLIN: G Maguire; N Corcoran, P Kelly, R Trainor; P Schutte, J Boland, S Durkin; J McCaffrey (0-1), M Carton; C McCormack (1-0), R O'Dwyer, L Rushe; R O'Carroll (1-0), D Sutcliffe (0-3), P Ryan (0-9, 0-8f, 0-1 '65').

Subs used: S Lambert (0-1) for Trainer, D Treacy (0-1) for O'Dwyer, O Gough for Schutte, N McMorrow (0-3, 0-1f, 0-1 '65') for McCormack, A McCrabbe (0-1, 0-1 '65') for Carton; Extra-time: R O'Dwyer for Boland, M Quilty for McCaffrey, D Plunkett (0-1) for Ryan, P Carton for O'Carroll, E Dillon for Treacy.

GALWAY: F Flannery; K Hynes, D Collins, G O'Halloran; N Donoghue, F Moore, T Og Regan; D Burke (0-1), B Daly; C Cooney (0-1), N Burke (0-5, 0-4f), C Donnellan (0-2); D Hayes (0-2), J Canning (0-12, 0-6f), D Glennon.

Subs used: I Tannion for Canning (blood sub), B Burke for Cooney (blood sub), J Coen (0-1) for O'Donoghue, I Tannion for Daly, J Regan (0-1) for Glennon, P Brehony for Cooney, B Burke for N Burke. Extra-time: P Sheil for Hynes, J Glynn (0-1) for B Burke, N Burke for D Burke.

Referee: Barry Kelly (Westmeath).