Even the qualifier system's most ardent advocates could hardly have anticipated the damburst of happiness released by this new format. Saturday evening in Hyde Park, Roscommon, saw a thrilling match decided at the death after the best part of two hours' football.

Westmeath emerged from it all with their climbing reputation still on the ascent, their first major scalp taken and an All-Ireland quarter-final place to look forward to. At the end, their supporters flooded onto the field - shining jubilation in the fading light.

Damien Gavin's winner for Westmeath in the second last minute of extra-time was oddly appropriate. A substitute, he had captained the county minors to that All-Ireland in 1995 and now earned the plaudits of manager Luke Dempsey for waiting patiently on the bench until his chance came.

It was doubly appropriate because its execution was so decisive and clear-headed. In the death throes of both normal and extra-time, players' heads were spinning. Wild shots, frantic scrambling and the irresistible lure of the killer goal even when it was plain that points would do more than merely wound.

Gavin's express solo from the half-back line took him deep into Mayo territory. The field opened up in front of him and the defence parted. The clock was ticking down. He was in the goal zone but, to his memorable credit, wound up his arm and clinically punched what was the winning point.

There had been so many potential turning points. Westmeath started as if they would cut Mayo to ribbons and led 0-5 to nil after 13 minutes. It could have been more. Ger Heavin was the focus of their attack and he played the part, getting onto ball he had scarcely a claim on and using possession well. Eventually Ray Connelly - who started in that corner - steadied the ship but early on Mayo's defence was taking water.

Mayo gradually came to terms with the match as David Brady began to motor at centrefield and Trevor Mortimer, particularly, and Kieran McDonald began to exert pressure. Westmeath's most abiding lesson of the evening must be that Heavin and the forwards won't do much without the ball. Distribution from the back was poor and frequently flew out over the sideline or straight into the pocket of a defender.

A goal on 30 minutes re-established Westmeath's command, Michael Ennis finishing well after Heavin had half-hopped the ball through as he tried to control it. Martin Flanagan could have had another but fired wide just before half-time.

The second half was a wasteland for the winners. They got to plenty of ball - Rory O'Connell was exceptional in his hard work and possession winning, even if his distribution was wild - but seemed to spill it or otherwise lose it and Mayo won all the breaks. As a result, the Westmeath attack had few chances and what came in was vigorously defended by the Connelly brothers and James Nallen in particular.

The Connacht finalists simply reeled them in, despite the excellence of some of the defending by Westmeath's David Mitchell at full back and his corner men, John Keane and Fergal Murray. With Mayo two points ahead and two minutes - actually seven when injury-time was taken into account - left, it looked like curtains for a Westmeath side that had only managed one point all through the second half.

Yet, somehow, they responded and Mayo failed to shut them out. Paul Conway pointed and Heavin kicked a free. In the dying seconds he had another for the match but it was too long a distance and extra-time loomed.

Again Mayo had the whip hand. Substitute David Nestor ran tirelessly at Westmeath and pressure turned into scores. At one point they led by three, their biggest margin all afternoon. Of ultimate significance was Damien Healy's point just at the end of the first period. This cut the deficit to two and gave Westmeath something to aim at.

"We kept plugging away," said manager Luke Dempsey afterwards, "and the belief in the team that there would be little in it at the end - we didn't know whether we would overturn a two-point deficit but that shows the spirit in the group".

The scores were epic. Des Dolan - having come on despite "being in agony every time he moves for a ball" according to Dempsey - potted a sideline ball from the wrong side for him to equalise in the 98th minute.

"I was down here with Frankie (Dolan, his cousin who plays for Roscommon) the week before the Connacht final practising shots with him," said Dolan afterwards.

"The two of us were messing on the sideline and had a shot like that. I got mine over first time off and then again here today." Would he like to play his cousin in the quarter-finals? "Ah yeah. I'll have to go up and give him a box," he replied - a less than oblique reference to Frankie's taking of a phantom punch in the Connacht final.

In the delirious aftermath, Dempsey is flushed with relief, but concerned over injuries. "I'm thrilled for the players. We knew coming here that we might have a slight advantage having come from four games we won whereas Mayo were coming in after a last-minute loss to Roscommon here. But we also knew we were coming in against a very experienced team so it would take all our courage and intensity of play.

"We will refocus, see if the players are alright, name the team and start again. We are now very depleted. We had 24 out of 28 players there today and now it looks like it may be less and Fergal Wilson will be a huge loss. We'll have to reassess it."

Mayo are now bystanders at the party and slowly shuffle off. Manager Pat Holmes is one of the last in the dressing-room. "The lads are very, very disappointed. That's the second time in three weeks that we've lost a very close game but you have to be ahead at the final whistle.

"But we're not the only team that suffers heartbreak and at least we're up there on a regular basis. The National League is something to take out of the year - it just didn't happen for us in the championship."

Westmeath? "I would say that no team will fancy meeting them."