Referee Niall Barrett's final whistle inspired a curious phenomenon. The skies darkened over Dr Hyde Park and rain cascaded down as if to mourn the passing of Roscommon's strong hopes in this season's Connacht football championship.

If Roscommon were firm favourites, Leitrim were a team in transition, looking to blood four or five young players so that the future would hold the promise that was absent in recent years. The visitors had been written off by everyone but themselves.

Leitrim manager Joe Reynolds succinctly captured the essence of a remarkable victory. "We had 15 players who were prepared to die for the jersey. They knew that they had been written off but weren't prepared to accept that fate. We have worked so hard all year and, importantly, we believed in ourselves and each other."

The strength of their faith must have been severely tested at times. Trailing by seven points (3-3 to 0-5) after 26 minutes and having just conceded two goals inside a minute, Leitrim would have been forgiven if they had accepted their fate. Instead they scored three points in succession and by half-time had reduced the deficit to five.

The interval allowed them to regroup which they managed in exemplary fashion, producing a stunning second-half display. When debutante left half back Dermot Reynolds fisted the ball to the net on 47 minutes, after the outstanding Gareth Foley knocked a high ball from Paul Kieran in his direction, the sides were level and the contest began in earnest. Tiny in stature but inspiring in his workrate, right half forward Foley roamed to great effect, snaffling loose ball and carrying it forward with elan, slipping tackles and creating space for those around him. In a monumental team performance, he stood out. Young corner back Michael McGuinness, Ciaran Murray and Kieran were others to inspire their team-mates while captain Seamus Quinn produced a towering second-half display. It was fitting that he should kick the winning point.

Roscommon's mental rather than physical application must be questioned. They had the advantage of having played a match, against London, so it wasn't a question of being caught cold. Flattered somewhat by a seven-point lead in the first half, they nevertheless produced excellent football: unfortunately it was sporadic and they never sustained the impetus. A propensity to squander gilt-edged chances meant that they never quite managed to put Leitrim away. Maybe they didn't harbour a fear of failure.

The decision to try to isolate young full forward Gerry Lohan - he had an outstanding match - and the speedy Frankie Dolan on their respective markers close to goal, proved a lucrative strategy. Lohan grabbed a goal, Dolan another and midfielder John Gillooly a third as the home side enjoyed a period of dominance that suggested that they could dissect the Leitrim defence at will.

However, when under pressure in the second half the strong running of the midfield and the half-back line, which had offered options in attack, disappeared. Lohan, who had given John McKeown a torrid time in the first half, was starved of possession. Roscommon simply overplayed the ball in cluttered corridors around midfield until dispossessed.

Donal Casserley and Gillooly had dominated midfield in the first half in breaking and fielding ball. Leitrim cleverly crowded this sector in the second half, and it worked to great effect. The forays forward of the excellent Michael Ryan and Clifford McDonald became less frequent.

Roscommon will reflect on some appalling shooting during the last quarter when a little composure might have saved them. Leitrim proved the quicker to settle, profiting from their opponents' tendency to concede frees. Kieran three times punished Roscommon with the placed ball, the only response a Lohan point.

Gradually, though, the home side established a pattern to their game, using the strong running of the half-back line and looking for early ball to Lohan and Dolan. The former finished superbly when put through on 19 minutes, but it was the brace of goals in a minute that suggested a seminal moment in proceedings.

Frankie Grehan's mis-hit free rebounded fortuitously to Gillooly, one of four players under the high ball, and he maximised the advantage by slipping the ball past Gareth Phelan. Within 60 seconds the Leitrim goalkeeper was faced with a one-on-one again, this time being beaten by Dolan.

Leitrim's three-point salvo just before half-time was followed by another two without reply after the interval before Reynolds' tour de force. His goal infused his teammates with fresh enthusiasm as they fought for every ball. The teams shared four points and a draw appeared likely when Quinn, on 69 minutes set off on a 30-metre run past several tacklers and finished with a point.

Roscommon's desperation to secure another score was manifest in a couple of dreadfully-miscued shooting opportunities. Barrett's final whistle, three minutes into injury-time, was greeted by disbelief on the part of the Roscommon players and elation for their opponents.

Leitrim could even afford to have corner forward Aidan Rooney sent off in the dying minutes for a blatant foot trip on Roscommon midfielder Casserly, as the latter raced into the Leitrim half. It resulted in a 45-metre free but substitute Eddie Lohan saw his kick drop short.

Reynolds remained pragmatic despite the euphoria. "It is only one match," he said. They won't de discounted lightly again.