Supersub Eoin Bradley pounced three minutes from time to propel Coleraine into the Irish Cup semi-finals with a pulsating 3-2 win at Inver Park.
Larne twice led through a Lyndon Kane own goal and Jeff Hughes header, only for the Bannsiders to respond through James McLaughlin and a Stephen Lowry penalty.
But the headlines belonged to Bradley, a first-half replacement for the injured Ian Parkhill, who won it with his eighth goal of the season in the dying minutes.
Latching onto a Jamie Glackin header the muscular striker spun Larne defender Harry Flowers before driving a low shot past Conor Devlin at his near post.
Larne had bossed the first half and were deservedly ahead at the break thanks to an own goal from Coleraine defender Kane.
Marty Donnelly, who struck the bar with an early dipper, whipped a 44th minute free-kick across the area and the ball ended up in the net off the top of Kane’s head.
Coleraine were level in the 54th minute when McLaughlin produced an instinctive finish for his 11th goal of the season, latching onto a Bradley header to volley into the bottom corner.
Larne were back in front in the 64th minute when Donnelly whipped another free-kick to the back post where Hughes planted an unstoppable header past Chris Johns.
But it was 2-2 in the 70th minute when Coleraine midfielder Lowry kept his cool from the penalty spot after John Herron handled inside the area.
Coleraine, second in the league and chasing a domestic treble after lifting the League Cup a fortnight ago, won it in the 87th minute when Bradley fired home in front of the travelling support.
