Republic of Ireland visit Wales to finish off 2018 FIFA World Cup qualifying, with a win for eithier team guranteeing them at least a spot in the playoffs.
So much on the line
Both Wales and the Republic of Ireland made the last major tournament, the 2016 UEFA European Championships, but only one of them can make next year's World Cup in Russia - although it's a possibility that nethier of them could.
A draw between the nations, just like there was in Dublin earlier in the campaign would eliminate Ireland outright and would leave Wales relying on a goaless draw between Croatia and Ukraine who have a similar win or bust scenario in Group I also on Monday.
On the other hand both Chris Coleman and Martin O'Neil's teams could still win group D if leaders' Serbia failed to beat Georgia at home, although it seems unlikely with Georgia having not won a game in nine qualifiers.
Wales have no fresh injury or suspension concerns, but of course they are missing talisman Gareth Bale through injury.
Ireland have left sided midfielders James McClean and Robbie Brady available again after both were suspended for the 2-0 win over Moldova on Friday night.
Young Callum O'Dowda got his first international start on Friday, but O'Neil would be a very brave man not to bring back in joint top scorer in qualifying McClean who has three goals to his name or the talented Brady.
Wales have won just one of their last 10 games against the Republic Of Ireland and none of their last seven.
Jason Koumas was the last Welsh player to score against the Irish when he grabbed two in a November 2007 clash.
Wales haven't won four consecutive matches since a run of six wins in a row back in 1981 under manager Mike England.