A Celtic treble is gone, but the recriminations, anger and sense of injustice will linger and fester for some time to come. Cup defeats to Inverness are rarely a tranquil affair. On a fateful night in Glasgow 15 years ago the Highlanders inflicted the first of their damaging, deeply defeats on Scotland's champions. They've made a habit of it down the years. Yet in a re-enactment of the night Caley went ballistic their players celebrated David Raven's late, extra-time strike by sliding joyously on their fronts before a small, delirious support. David Raven (second right) celebrates with his Inverness team-mates following his extra-time winner . The celebrations continue on the pitch as Inverness rejoice in reaching the William Hill Scottish Cup final . They will be back here in greater number for this club's first ever Scottish Cup final against Falkirk – a former club of manager John Hughes - on May 30 where they will be favourites to triumph. 'That doesn't sit nice with me,' said Hughes afterwards. 'I love to be underdogs. I love to create a siege mentality.' This dogged, energetic Inverness side – driven on by their man of the match captain Graeme Shinnie – perform better as underdogs. Yet who can dispute they now have an outstanding chance of winning their first major trophy, a mere 21 years since the acrimonious amalgamation which led to their entry to the senior ranks? Before then comes weeks of uproar. Days of Celtic anger, finger jabbing and injustice over the standard of officiating here. Not, it must be said, without justification. The standard of Scottish refereeing remains an ongoing embarrassment. Supporters of other clubs believe Celtic have had their share of favourable decisions down the years. If that's true this was a pretty savage slice of karma. Virgil Van Dijk (centre) fired Celtic into an early lead with a superb free-kick in the 18th minute . A goal to the good via Virgil van Dijk's superb 16th minute free-kick the Parkhead side were denied a clear penalty kick – followed by an Inverness red card for Josh Meekings - before half-time. Celtic's Stefan Johansen was deftly played through on goal, his shot parried across goal the face of goal by Inverness keeper Ryan Esson, where Leigh Griffiths seemed certain to score with a swooping header. The hand of Meekings blocked the ball, yet additional assistant referee Alan Muir - standing five yards away – failed to see it through the bodies in his way. With Meekings off and a chance to make it 2-0 from 12 yards this could easily have been the Celtic walkover people expected. Where Inverness are concerned, we should all know better. Four times in the last 15 years they have denied their more feted opponents big victories in league and cups at a critical juncture. Greg Tansey shoots past replacement goalkeeper Lukasz Zaluska to equalise for Inverness . And the turning point for this latest triumph came in 53 minutes. In a bitter, unpalatable irony for Celtic supporters it came from a penalty. And a red card for their keeper Craig Gordon after he upended Marley Watkins as he outstripped Adam Matthews and hared in behind the Celtic defence. The decision to dismiss the Celtic keeper was correct. That the officials had gone this one right – while making such a hash of the first half equivalent – was of no consolation to Celtic's players and management at time up. Ronny Deila began a slow, menacing trudge towards the other side of the pitch to confront referee MacLean and his officials. His captain Scott Brown, making his a little too forcibly, had been dragged away seconds earlier. 'I didn't say so much,' said the Norwegian. 'I just asked if he knew what he had done. That's it. He didn't know. He hadn't seen it.' Virgil van Dijk's post match protestations were strong enough to earn a booking. Edward O'Fere gave Inverness the lead in the 96th minute despite the attention of Van Dijk . 'Everybody of course gets angry,' added Deila. 'But that's why football is interesting, it's a tough world, that's why it's so hard to get the treble. It's small details that can make you fail and today it was a small detail that made it hard for us.' To say so, however, is to overlook a rather large obstacle in Celtic's way; Inverness. For Lukasz Zaluska, Craig Gordon's deputy, the task of keeping Greg Tansey's penalty out with his first touch was a tall order. James Forrest had also been sacrificed in a tactical manoeuvre and suddenly Inverness, with their one man advantage, had the legs and the running. On a diet of three games a week the champions elect looked tired and leggy, their bench options limited. With Forrest gone they were neutered. Who could have predicted that when they began the game with purpose and intent? Nir Bitton smashed a first time right foot shot off the junction of post and bar in 12 minutes. Four minutes later they took the lead with a superb strike from van Dijk. John Guidetti levels matters in the 116th minute with a well-taken free-kick . Inverness defender Gary Warren was booked for a crude - if vital - foul on Forrest on the edge of the box as the Celtic winger threatened to use his pace to rampage the Inverness support. Van Dijk took the free kick, curling a magnificent right foot effort into the top left hand corner of off the inside of the post. On league duty last week Inverness had recovered from the loss of an early goal and so it was here. In last season's League Cup Final defeat to Aberdeen in Glasgow the team in blue stood accused of being dour and unadventurous. The same couldn't be said here. Whatever the Celtic injustices, they can hardly deny their opponents played to devastating effect on the break. They should have been out of the game by half-time. Celtic had the chances. Yet their captain Graeme Shinnie had an outstanding game, proving the man of the match. When the highlanders equalised they were the stronger sharper team. A weary Celtic clung on slightly for extra-time. And in 95 minutes it seemed they were broken when Shinnie's cross from the left touchline ricocheted off the knee of Marley Watkins into the path of striker Edward Ofere. The Nigerian, who had blown a golden opportunity to level in the first half, guided his shot low and true past the outstretched left hand of Zaluska. Craig Gordon might have made the save. In every sense Celtic looked weak and vulnerable now. They weren't out of it completely. Not yet. Celtic players stand dejected on the pitch following their 3-2 loss . In a personal disaster for Inverness stand-in keeper Ryan Esson – who had enjoyed a fine game beforehand – allowed a swirling John Guidetti free-kick to bounce over his outstretch hands and into the net for 2-2 12 minutes into extra-time. Inverness could – should have had a second penalty when the unconvincing Zaluska clattered his fists into the back of Ofere in 108 minutes. But they wouldn't be denied. With four minutes of extra-time to play. David Raven, castigated by his manager before extra-time, slammed the ball into the net from an acute angle after more outstanding work by Shinnie, driving into the area and hammering the ball across the face of goal. 'Coming into extra time he was sitting down,' said Hughes in some disgust afterwards. 'I grabbed him by the scruff of the neck and told him to stand up because sitting down is, for me, a sign of weakness in those circumstances.' Such was the Inverness strength that Celtic were done. They were gone. Their upporters drifted away silently, but in the days to come they will have plenty to say. And for Scotland's referees there will be no avoiding the din.
Virgil van Dijk gave Celtic the lead with a superb free-kick .
Josh Meekings escaped a red card just before the break for a hand ball .
Celtic keeper Craig Gordon was sent off early in the second half .
Greg Tansey's penalty and Edward Ofere put Inverness ahead .
John Guidetti equalised, but David Raven had the final say .