Craig Samson, the St Mirren goalkeeper, assumed hero status as his stunning save from Aberdeen rookie striker Cammy Smith in a dramatic penalty-kick shoot-out took the Paisley side into the semi-finals of the Scottish Communuties League Cup following a compelling quarter-final last night.

Samson had watched Stephen Hughes' spot kick – Aberdeen's first – hit the bar easing the pressure on the visitors, but when Smith, brought on late in regulation time to bolster the home attack after they had fallen behind to a Kenny McLean strike, shot to Samson's right, the keeper stretched to make the save.

Josh Magennis, moved from full-back to a striking role in a bid to gain parity for the Dons, grabbed an equaliser two minutes into time added on to set up extra time followed by the shoot-out in the tightest of ties.

Danny Lennon, the Saints' manager, was understandably delighted, declaring himself a proud man who described his players as gladiators. "The character the boys showed was first-class," he said. "To lose the lead in the dying minute of the game was very difficult to take and the boys showed great character to take us over the line and take it to penalties. If every game was like that, stadiums would be full across the country. In think both sets of fans were entertained throughout. It was a good game of football to watch."

Aberdeen manager Craig Brown could not hide his disappointment and was understandably down at missing out on another semi-final appearance, but he called on his side to refocus quickly.

"We should have been 3-0 up after five minutes," he insisted, "but St Mirren took their chances and that is what enabled them to progress.

"We can't allow this to affect our league form. We have to take it on the chin, take a deep breath and make sure we recover at the weekend."

The home side's exuberance was evident in the opening stages when Niall McGinn came close and Russell Anderson had an effort blocked on the St Mirren line.

But when Sam Parkin's back-post header, after Aberdeen goalkeeper Jamie Langfield flapped Steven Thompson's looping header into his path, gave the visitors the impetus they needed, they began to carve out chances, particularly down the right through David van Zanten, as well as a thunderous 25-yard free-kick from Jim Goodwin which the Aberdeen keeper did well to punch clear.

Aberdeen, seeking a 13th game without defeat, responded with a series of attacks and when Clark Robertson sent a high ball into the Saints' area in the 22nd minute, Vernon saw Samson well off his line and cleverly headed the ball over him and into the net.

It was clear that, certainly in the midfield, there was a battle for territorial advantage with Gavin Rae and Isaac Osbourne working hard to hold off Goodwin and Kenny McLean, whose quick-thinking, not to say an absence of Aberdeen defenders, brought the goal that put his side ahead in the 69th minute.

McLean found space on the left and from 15 yards hit an unstoppable shot with Langfield, sucked off his line, also at fault.

With Brown having restructured his team to combat this setback, however, better things were expected and when Fraser replaced Vernon with 12 minutes remaining, it brought new verve to the home side.

In addition, Magennis was offered another chance to show his worth as a striker and his move from right-back was to be manna from heaven for the men in red.

Pushing hard for an equaliser and with referee Crawford Allan preparing to conclude regulation time, the Northern Ireland internationalist stuck out a foot as Cammy Smith's 92nd minute shot came across the penalty area and the touch was enough to deflect the ball past Samson and to put this tie into extra time.

Hughes might have wrapped things up for the Pittodrie side early on in this period, but was frustrated to see his header hit the bar as St Mirren continued to try and counterattack.

Such a tactic nearly worked as Lewis Guy found himself clear in the Aberdeen area but while Langfield appeared to have made contact with the substitute, the referee decided, instead, that it was simulation on the striker's part and he was shown a yellow card.