Sasa Kalajdzic dealt the Republic of Ireland a late blow in Linz with the only goal in Austria's 1-0 Nations League victory at the Raiffeisen Arena.
The result ensured that, no matter how the closing contests in Group B play out, Austria sealed promotion to League A.
Ireland enter Tuesday's critical home clash at the Aviva Stadium in third place, with one point fewer than their final opponents, Kosovo.
Heimir Hallgrimsson's men were not without chances, but only Kalajdzic made one count when he broke the deadlock in the 79th minute.
