I’d say The Civil Wars may be a little sorry they invited The Lumineers out on the road for their European tour. Joy Williams and John Paul White have a history of picking decent support acts (James Vincent McMorrow did the business for them on a recent jaunt around America), but even the Grammy-winning duo could have bitten off more than they can chew this time around.

The Lumineers don’t play like a support band. Only a few songs in, and the drummer/mandolin player/ backing vocalist/ Woody Harrelson lookalike (the wonderfully monikered Jeremiah Fraites) is baiting a pretty packed Olympia into dividing down the middle into two sets of vocalists for the uber-catchy ‘Hey Ho’. The five-piece country rock band from Colorado are more confident than fifth years in a south Dublin boarding school (and that’s saying something), as they give most of their eponymous debut album a judicious airing.

Starting with acoustic guitar, bass, drums, keyboard and cello, they swap instruments throughout, and even have a second kick-drum located at the front of the stage for added percussive oomph when the mood demands it. Their entire set is a highlight, but particular mention must go to ‘Classy Girls’, a beautifully tongue-in-cheek take on picking up the ladeez on a night out, delivered perfectly by affable frontman Wesley Schultz. They leave the stage to tumultuous applause and calls for an encore and are, quite simply, the best support act I’ve ever witnessed – the fact that their February 2013 gig has been moved from Whelan’s to the Olympia is proof positive that their star is very much in the ascendant.

Trying to follow the sheer rambunctiousness of The Lumineers would be a tough ask for anyone. Even moreso for an acoustic duo with just one guitar between them. Credit to The Civil Wars that they almost pull it off.

Appearing on stage in muted black, the duo have their banter and moves down pat – indeed, it seems a little studied at times and Joy’s vocals do tend towards the overwrought. But there’s something undeniably powerful about the way their voices swirl in and around the guitar, blending together on the sublime ‘I’ve Got This Friend’, the heart-halting ‘To Whom It May Concern’, the classic country of ’20 Years’ and the raucous ‘Barton Hollow’. They also do covers better than almost any other act I can think of, and tonight’s set includes a stunning take on Portishead’s ‘Sour Times’ and an almost unrecognisable ‘I Want You Back’, while the encore’s brilliant bluegrass ‘Billie Jean’ brings down the house.

Great as it was, even that couldn’t match the brilliant shine of The Lumineers, whose warmth and willingness to engage made for one of those ‘where were you when’ live events.