The two sides are level on 11 points and know that victory would pile the pressure on second place Sweden
Republic of Ireland and Austria go head-to-head on Tuesday night with both sides desperate for the three points that will give their World Cup 2014 qualification hopes a massive boost.
Both sides are currently level on 11 points in Group C, three points behind second-placed Sweden, who came away with a hard-fought 2-1 victory over Giovanni Trapattoni's side in Dublin on Friday.
Austria, meanwhile, go into the game in Vienna on the back of a 3-0 defeat to runaway leaders Germany.
A place in the play-off round for Brazil 2014 is still possible for both sides, but both need three points from the clash at the Ernst-Happel-Stadion to keep their hopes of catching Sweden alive.
Ireland's task will be made all the more difficult by the fact that they have not won a competitive fixture in Austria since 1958, but Marcel Koller's men had to rely on a late David Alaba equaliser to secure a 2-2 draw in the reverse fixture in Dublin in March.