Kevin Nisbet's stunning strike condemned former club Hibernian to a first defeat in 18 Scottish Premiership games and moved Aberdeen level with the Easter Road club as the race to finish third took another twist.
As a drab contest entered its final stages, Scotland striker Nisbet controlled a Graeme Shinnie cross on his chest, before arcing a dipping volley over goalkeeper Jordan Smith and high into the Hibs net.
It earned Scottish Cup finalists Aberdeen a first win over Hibs this season and moves them level on points with their visitors with four games remaining.
David Gray's side do retain a significant goal difference advantage and carried plenty of threat at Pittodrie.
Martin Boyle shot just past a post early on after Aberdeen had played themselves into trouble, and Josh Campbell and Rocky Bushiri went close, too.
Bushiri played his part at the other end, blocking efforts from Pape Habib Gueye and Topi Keskinen.
But the fact neither goalkeeper had a significant save of note to make tells the story of a frustrating opening 45 minutes.
Hibs were quick out of the traps in the second half, Campbell and Bushiri again going close with headers. But it was Aberdeen who had the ball in the net on 68 minutes, only for Nisbet's effort to be ruled offside.
The striekr wasn't to be denied, though, and broke the deadlock with a genuine goal of the season contender.
Aberdeen had a spring in their step after that and almost doubled their lead in added time when substitute Oday Dabbagh burst through but was denied by Smith.
Smith was called into action again to parry a Dante Polvara shot as Jimmy Thelin's secured a win which moves them up to fourth and on to the coattails of Hibs.