Wales host the Republic of Ireland on Monday, live on Sky Sports, with victory for either side guaranteeing them a World Cup qualifying play-off spot.
A win for either team will guarantee a November play-off at their opponents' expense and could yield an automatic qualifying spot if Group D leaders Serbia falter in their last game at home to Georgia.
For Wales, a draw at Cardiff City Stadium would be enough to finish above Ireland in the table - but not necessarily enough to nail a play-off place, with Croatia also in contention.
Wales boss Chris Coleman says his side will embrace the pressure of Monday's game, insisting his players will only be thinking of victory.
"We're on dangerous ground if we go in with a game plan of trying to soak the pressure up for 90 minutes," said Coleman, who will be without his attacking talisman Gareth Bale due to injury.
"We are too good to do that. We'll go and attack, go and score goals. We have to do that - it's our strength."
Wales have not lost at home in a competitive international since a 3-0 defeat by Serbia in September 2013, but Republic boss Martin O'Neill believes his side have the beating of them.
"I think we can win the match," he said. "I felt it was always going to be like this. When we get off to a decent start, the mindset changes a little bit in terms of points.
"But if you had said to me right at the beginning when the group was drawn that we'd have to go to Wales and win - and we were down as fourth seeds - I would have taken it. So let's go for it."
Team news
In Bale's absence, Derby County forward Tom Lawrence scored a fine first international goal to give Wales a 1-0 win away to Georgia on Friday.
Lawrence impressed Coleman with his all-round performance, meaning Liverpool's Ben Woodburn could be on the bench again.
Ireland midfielders James McClean and Robbie Brady were both suspended for Friday's win over Moldova, with Callum O'Dowda getting his first international start.
And O'Neill admits he will now have to deal with some "interesting" selection issues for the clash in Cardiff.
"We have some pretty decent players coming back. James McClean has been fantastic for us in this tournament and Robbie Brady is a very, very good player."
Opta stats
Wales have won just one of their last 10 matches against Republic of Ireland (D4 L5) and none of the last seven.
Wales have failed to score in five of their last six against Ireland, with Jason Koumas scoring their only two goals in this run back in November 2007.
Wales haven't won four consecutive matches since a run of six under Mike England in May 1981.
Daryl Murphy is averaging a goal every 55 minutes in World Cup qualifying for Ireland (three goals scored in 166 minutes).