Veteran defender Lee Mair scored the only goal of the game with seconds to spare and sent St Mirren into the draw for the quarter-finals of the Scottish Communities League Cup.
It was a victory their pressure undoubtedly merited but it wasn’t a display to savour against opponents who have yet to win a match in the First Division this season.
As spectators braced themselves for extra time, goalkeeper Kevin Cuthbert, who had been excellent throughout, failed to claim a corner from Graham Carey and Mair, unchallenged, headed home from six yards.
The visitors set out as if they intended to park the bus but they squandered a glorious opportunity to take the lead in the fifth minute. James Keating was the architect, holding the ball up superbly before releasing Louis Longridge on the right. The winger was left with only keeper Craig Samson to beat from 12 yards but lacked composure and fired wide.
Jon Routledge found himself in a similar position after accepting a reverse pass from Ali Crawford but Samson stayed on his feet to block the midfielder’s shot.
With Saints failing to make any impression, manager Danny Lennon sent on last season’s top scorer, Steven Thompson, for the ineffective Lewis Guy after only 35 minutes.
The switch almost paid immediate dividends when Thompson’s chip from the edge of the penalty area beat Cuthbert but landed on top of his net.
Unfortunately, the Buddies proved to be as devoid of inspiration after the interval as they had been before it and they were reduced to shooting from distance.
By then Accies had given up all pretence of attempting to win the game in standard time or even of crossing the halfway line, content to soak up the pressure and wait for penalties.
Cuthbert produced the save of the evening in the 77th minute, throwing out his left arm to push Mair’s powerful header from a Carey corner behind.
Substitute Ziggy Gordon became the first player to be cautioned in the 84th minute when he pulled down Paul Dummett.