Celtic's dreams of a Treble came unstuck at Hampden this afternoon after Inverness pulled off a late extra-time winner to dump them out of the Scottish Cup.

It looked as though it was all going to plan for Celtic when they headed into the interval a goal in front but it quickly went wrong when Craig Gordon was red-carded for bringing down Marley Watkins shortly before the hour mark.

Inverness levelled from the spot and with 10 men and a substitute goalkeeper who looked ill at ease, Celtic never re-found their composure.

Inverness took the lead for the first time in the game through Edward Ofere, a goal that was cancelled out by Hoops sub John Guidetti. As the tie looked to be heading towards the lottery of penalties, David Raven netted the winner with just three minutes of extra-time remaining to send Inverness into the Scottish Cup final and end all of Celtic's Treble talk.

It was Nir Bitton who almost drew first blood when he had a shot cannon off the cross bar, but it was Virgil van Dijk who opened the scoring when his super free-kick curved over the Inverness wall and clipped the inside of the crossbar before bouncing across the goal-line.

James Forrest had been the architect of the move, inviting Gary Warren to halt his progress in the crudest way and the resultant set-piece was where Celtic exacted their revenge.

In the immediate aftermath of the goal, the Parkhead side looked certain to add to their lead.

Stefan Johansen spurned a glorious opportunity to double their lead, although at the other end Ofere ought to have done better when an inviting ball fell at his feet in the box but he sent his shot wide of the target.

On the cusp of the interval Celtic were denied a penalty when Leigh Griffiths' header was punched off the line by Josh Meekings. Referee Steven McLean missed the infringement, while neither the linesman nor the additional assistant flagged up the offence despite the visceral protests from the Celtic players.

There was further controversy after the interval when Gordon was shown a straight red-card for bringing down Watkins. The keeper slid in as the Inverness midfielder closed down on goal and the shrill whistle of McLean sounded immediately.

Deila sacrificed Forrest and sent on Lukasz Zaluska, but the keeper's first task when he got onto the pitch was to pick the ball out of the net after Greg Tansey kept his head to convert the spot-kick.

Celtic tried to regroup - Johansen came close with a long dipping effort that was touched over the bar - but they were spooked at the back and Inverness worked hard to turn the screw.

Zaluska looked ill at ease and anxious at the back, with his uncertainty unsettling those in front.

Watkins had two good chances to put Inverness on the front foot but scorned both.

As regulation time drew to a close Celtic lost Commons through injury as Aleksandar Tonev was introduced to the fray - his first appearance for the club this year.

The game headed into extra-time with Zaluska tested first as he batted away a decent effort Ryan Christie. Within minutes, though, he was picking the ball out of the net for the second time when Ofere drilled a low effort into the bottom left-hand corner.

Celtic responded with Guidetti taking over from the Griffiths and it was the Swedish sub who drew Celtic level. His free-kick bounced in front of Ryan Esson who hit the deck and the ball somehow ended up in the back of the net.

It was Inverness, though, who had the last laugh when Graeme Shinnie's drive across the face of the goal was converted by Raven to give the Highlanders a ticket into the Scottish Cup final.

Deila said: "I don't think I have to say too much about it [the handball that was not spotted by officials before half-time]. People can see for themselves.

"We had control and created big chances in the first half. We should have scored more. The game switched when we got a man sent off and we lost the ball too much as the players got tired.

"There is no problem with our red card. If it is a penalty, it is a red card.

"We give credit to Inverness and start concentrating on a big game in the league on Wednesday. The most important thing is the league.

"You get disappointment in football and you need to deal with failure. Today was a big day and we were close."