The holders progressed into the quarter finals of the Scottish Cup as a last-gasp stunner from substitute Jordan Roberts separated Inverness and Motherwell at Fir Park.

An own-goal from Stephen McManus had the visitors ahead, but a Scott McDonald equaliser in the second-half from a well-worked corner looked to have earned Motherwell a replay, which probably would have been about right on the balance of play.

That was until the intervention of Roberts, whose arrow of a strike settled the affair with barely a minute of added time remaining.

The first half was short of incident as both sides cancelled the other out for long spells, but at least the woodwork was troubled at either end.

There looked to be little danger as Inverness right-back David Raven swung a hopeful ball into the Motherwell box, but Miles Storey arched his back brilliantly to loop a header up and over Connor Ripley. Just as it looked to be dropping in though, Ripley stretched up his hand and managed to help it onto the bar.

McDonald then headed against the bar at the other end when he might have done better, getting on the end of Marvin Johnson’s whipped ball and glancing up onto the woodwork.

Inverness took the lead after 39 minutes, and it was a lapse in concentration from Motherwell and a moment of initiative from Carl Tremarco that made the difference.

A poor pass into Motherwell’s right-back area was left by Josh Law, not spotting the apparent danger from the overlapping Tremarco.

The Inverness left-back got to the by-line and drilled the ball across the six-yard area, where Storey missed his contact and the ball ricocheted in off of the luckless McManus.

Motherwell huffed and puffed in the second half without creating too much, and the frustrated fans were crying out for top scorer Louis Moult to be introduced to the action.

Just as he got stripped for action though, the home side drew level.

A clever corner kick routine saw the ball floated up for McManus to attack arriving late in the area, and his powerful downward header was helped on its’ way into the net by McDonald.

Moult put his tracksuit top back on much to the annoyance of the home crowd, and as a result the game settled down again into a midfield battle with neither side looking particularly likely to break the stalemate.

By the time Moult did enter the action, Inverness had regained their composure, and it was ironic that for all the attention surrounding a Motherwell substitute, it was an Inverness one that made all the difference.

As the clock ticked over into stoppage time, Motherwell midfielder Morgaro Gomis was barged over in the centre of the park, but as the home side waited for the foul, the visitors played the ball in to Roberts 35 yards from goal.

The forward sidestepped a challenge before unleashing a rocket into Ripley’s top right-hand corner to empty the ground and send the small band of Inverness fans behind the goal into raptures.