Watch: Irish fans rousing rendition of 'Fields of Athenry' in Cardiff
The Boys in Green can expect a hostile reception when they face Wales in Cardiff tonight but if they react as strongly to the opposition as the Irish fans did on the city streets this afternoon, then Martin O'Neill's men could well end up in a World Cup playoff.
The Green Army has invaded the Welsh capital ahead of tonight's crucial World Cup qualifier, with Ireland needing a win to claim a spot in the playoffs. The travelling fans are already in full voice judging by this video, overcoming a bout of Welsh boos to belt out a rousing rendition of 'The Fields of Athenry'.
The Irish team will need the supporters to be similarly passionate tonight as they look to quieten the Welsh fans and claim a huge win in Cardiff.
Watch the Ireland fans in full voice below: