Rangers reached the League Cup final after Ryan Naderi's late strike at Hampden finally breached a stubborn Aberdeen.
The win extends the Ibrox side's unbeaten run to 11 games, with either Hibernian or Hearts the obstacle in the final on 13 December as they seek their first silverware under boss Derek McInnes.
For all the positives among Aberdeen's performance, it is a fourth loss in five and a missed opportunity for manager Stephen Robinson to secure a much-needed statement win and enhance his own fine cup record.
Aberdeen last lifted this trophy under McInnes in 2014. Their wait goes on with Rangers within touching distance of capitalising on their impressive recent run of results.
The odds were stacked against the Pittodrie side with many believing this to be a formality, a routine stroll for Rangers. Not so.
Defensively depleted, Aberdeen still looked strong - albeit Ayoub Mouloua was a touch fortunate to escape an early handball.
Rangers had no shots on target until the 43rd minute but then went close three times before the break and swarmed all over their opponents after it, with Badredine Bouanani a constant threat.
Aberdeen held firm impressively until the breakthrough arrived late on with Naderi touching home after good work from Kevin Kelsy and James Penrice.