CLEARLY it had been pretty ridiculous that it took St Mirren 66 years to finally win the League Cup, but it was impossible to find a supporter who cared about boring old history last night.

They were overcome by the fun and exuberance of the present. Black-and-white ribbons are on the trophy at long last. Paisley has a civic hangover this morning after celebrating its first trophy since the 1987 Scottish Cup. That was 26 years ago. The closing minutes of this final, as they desperately defended a lead, seemed to take an age to pass too. How they erupted when it was finally all over.

They won a tennis rally of a final in which they were behind, then 3-1 up, then holding on for dear life as Hearts tried to batter their way to 3-3.

St Mirren have suffered countless painful visits to Hampden over the years but this was their day. Esmael Goncalves, Steven Thompson and Conor Newton scored – Ryan Stevenson got both for Hearts – in one of the most gripping recent cup finals.

Hearts and the League Cup don't go. Their 50-year wait to lift it again continues. They made as many chances in this final as they had in putting five past Hibernian in their last. They sang about that one during the match, and will do so again, but this game will quickly fade from their minds.

Their players gave Gary Locke all the commitment he had demanded on his first day as permanent manager but in three crucial moments their defending was not a match for St Mirren's attacking.

The winners did not make too many more chances than those they scored, but those were taken expertly. St Mirren effectively won the cup in half an hour. They had not shown much in the first half until equalising near the end of it, then scored twice early in the second period to give themselves what proved an unassailable lead.

Hearts scored before and after that burst of three St Mirren goals, but they didn't do enough. Michael Ngoo and John Sutton were a couple of battering rams in a 4-4-2 but after initially causing some damage they petered out.

The opening goal came when Jim Goodwin stuck out a leg to deny Ngoo and the ball flew to Stevenson. He wriggled this way and that, and the chance almost seemed to have passed, before he got away a shot which deflected off Paul Dummett's calf and past Craig Samson.

Ngoo and Sutton presented a combination of strength and height which frightened St Mirren at first. Sutton crashed a close-range header off the outside of a post and Ngoo was twice close to making a telling connection, the second after Mehdi Taouil's lovely little dribble opened up the defence.

St Mirren were holding on, but their key players grew into the game. Paul McGowan, Gary Teale, and Goodwin, and the three goalscorers, played big roles. The final turned when Thompson's crisp and clever through ball sent Teale racing in behind the Hearts back four. They howled for offside, as did 28,000 Hearts voices in the stands, but Danny Wilson had played him on. Teale's experience showed. Instead of taking the legitimate option of trying to score, he had the composure to see Goncalves was better placed. He squared to him and the equaliser was routinely buried.

It had taken St Mirren 37 minutes but their ability to open up the Hearts defence would come to define the match. Three of Locke's back four were young – Wilson, Dylan McGowan and Kevin McHattie – and with the captain, Andy Webster, they were caught too square. The whole lot switched off when a clearance came to Teale in yards of space, before their goalkeeper spared them. No sooner was the second half under way than they were exposed again, this time decisively.

In truth, St Mirren taking the lead was far more about Thompson than Hearts. Dummett's low cross from the left was inviting but it was Thompson's anticipation, positioning and finishing which resulted in him reaching it first to lash a strike past Jamie MacDonald.

St Mirren soon fashioned another excellent goal. Newton wrestled away from Taouil, then played a one-two with Goncalves. The Portuguese's return ball was delicious, weighted perfectly, and Newton latched on to it to powered in a right-foot shot. It was high-class play which deserved to win a final.

For Hearts, Ngoo became more ragged and frustrated the longer the game wore on. He was unlucky when Taouil overhit a cross to him and it deflected off him to force a Samson save, but otherwise he could not impose himself as Hearts wanted.

It would have helped St Mirren's blood pressure if they had calmly controlled the remaining 24 minutes, but they had to withstand a barrage. Their supporters will remember this only as a wonderful day but what a sweat they were subjected to before their men saw the job through.

Samson performed minor heroics to preserve St Mirren's lead. Hearts' late cavalry charge was pretty lumpen but it kept St Mirren pinned back, with Goodwin also holding them together. A Stevenson shot struck the bar, another effort was saved by Samson and the goalkeeper also denied McHattie.

The dam broke when Ngoo held off a defender and played a pass wide for Stevenson to score with a scuffed low shot across Samson and inside the far post. Including stoppage time Hearts had nine minutes to equalise. Nine is a significant number to St Mirren at Hampden: that's how many players Rangers needed to beat them in their last cup final. But this was their day and, for the first time, ever their League Cup.