THE first cup is the sweetest.

Time will tell how long Ronny Deila remains as Celtic manager but regardless of whether he stays for one season or 10 he will not forget this afternoon at Hampden in a hurry. The Norwegian, a man familiar only to football obsessives and hipsters as recently as 10 months ago, has spent the majority of his first season in Scotland trying to convince the sceptics and doubters that he is the right man to take Celtic forward. Here, then, was the first piece of evidence to further validate his claim.

Don't let anyone fool you that the bigger clubs - well, Celtic these days - are not fussed about the League Cup. Deila's reactions at full-time, after his team had deservedly beaten a Dundee United side reduced to 10 men early in the second half, were not those of a man trying to play the whole thing down. With a beaming Rod Stewart watching on, Deila collected the trophy at the end of the line and bounded excitedly down the stairs with it and on to the pitch. There followed not one Ronny Roar but four, Deila executing his trademark fist-pumping celebrations in front of each section of the Celtic support. He looked like a man in his element.

This was Celtic's 15th League Cup success, a first since 2009, and they did so without conceding a goal throughout the entire tournament, scoring 13 in the process. Not even a missed James Forrest penalty late in the game, after the winger and a visibly put-out John Guidetti had squabbled over who should strike it, could put a dampener on this occasion. By that point Celtic were two goals to the good and coasting to the finishing line, their supporters confident enough to turn their backs to the pitch for a mass huddle, before greeting every pass with a hearty ole! The party was already in full swing before the final whistle had even sounded.

This, of course, could well just be the start of it. The first part of the treble has now been secured and the two other parts remain within Celtic's grasp. They meet United again on Wednesday in a William Hill quarter-final replay, and sit three points clear at the top of the SPFL Premiership with a game in hand. Deila will need to come up with something quite special to celebrate should his team go on to scoop the lot.

Scott Brown was the man first up the stairs to collect the trophy. Of course he was. The prospect of the Celtic captain being dropped due to his exertions in midweek - when photographs seemed to show him the worse for wear after a night on the town - had always seemed fairly slim and there he was in his usual place, stripped and charging around the Hampden field in typically effervescent style, clearly none the worse for what Deila had labelled "a small mistake".

Brown's afternoon was relatively free of contention aside from one incident towards the end of the first half when he chased Ryan Dow into the Celtic penalty box and then seemed to ease him to the ground with a nudge in the back. It could well have been a penalty but referee Bobby Madden, after a moment's hesitation, chose not to award it. United, trailing by a goal at that point, cried injustice but if fell on deaf ears. They never really looked like scoring thereafter.

Brown's opposite number would likely have needed a stiff drink himself on Sunday evening. What a day this turned out to be for Sean Dillon, and not in a good way either. Injured in a robust collision with Virgil van Dijk that required seven stitches, the Irishman was deep in the bowels of Hampden getting treatment when Celtic got their noses in front after 28 minutes. United chose to play on with 10 men and it would prove a costly decision. With his marker temporarily absent, Anthony Stokes had the freedom down the left to fizz in a cross that Kris Commons diverted goalwards. Radoslaw Cierzniak made a terrific block to turn it on to his post but could do little to prevent Commons hammering in the rebound. It had the feel of an important moment in a match that had been fairly cagey up until that point and so it proved.

Dillon eventually re-appeared after six minutes off the field - poor Blair Spittal was seconds away from coming on to replace him, only to be told to take a seat again - but, two days shy of St Patrick's Day, this particular Irishman's luck was not to get any better. United had re-emerged from half-time still in the game at 1-0 down but the dismissal of their captain after 56 minutes effectively killed their chances stone dead. Dillon could have little complaints either, his lunge on Emilio Izaguirre both high and late. His earlier heroics - when he had cleared a van Dijk header off the line - had largely been forgotten by then.

The red card seemed to deflate United and Celtic, with the extra man, belatedly begin to play with a bit of a flourish. Chances came and went before they finally secured a second goal 11 minutes from time. It was a well-worked move involving Stefan Johansen and Guidetti, and adroitly finished by Forrest whose shot wrong-footed Cierzniak. Celtic should have had a third when the winger was hauled back by Paul Dixon, but after winning the right to take the penalty - the fans wanted Brown to hit it - his effort was tame and easily saved by the goalkeeper. It was the only bit of good fortune United enjoyed all afternoon. There was no doubt this was Celtic and Deila's day.