Former Dunfermline manager Jimmy Calderwood enjoyed a winning return to East End Park as his Dons side produced a back to the walls performance.
Recent signing Noel Whelan scored the only goal of the match as the visitors then hung on for dear life.
Calderwood is satisfied with his new team's start to the season but that cannot be said of his replacement Davie Hay who watched Dunfermline dominate the match without scoring. He must now pick them up for Thursday's vital UEFA Cup tie.
In a lively opening spell, home striker Noel Hunt tested Aberdeen keeper David Preece with a ferocious angled drive and then beat defender Russell Anderson before slipping the ball into the net only before the goal to be disallowed for a foul by the Dunfermline forward Craig Brewster.
The home team continued to press and it required an excellent piece of penalty box defending by Steven Craig to prevent Gary Mason from putting Dunfermline in front.
Brewster and Hunt are showing signs of developing the same kind of partnership that Brewster had last year with Steve Crawford.
But they were unable to grab a goal as Dunfermline dominated and they were punished in the 23rd minute when Aberdeen went ahead against the run of play.
Whelan ran onto a hopeful long throughball and flicked a shot over the fingertips of keeper Derek Stillie.
Dunfermline still looked the stronger team and Anderson was luck to stay on the pitch after kicking out at Hunt. Moments later defender Andrius Skerla failed to direct a wicked free-kick from Gary Dempsey into the Aberdeen net.
A long-range shot from Dons midfielder Scott Severin whistled just past the post but Dunfermline were quickly on the attack again with David Preece having to make a great block to deny Brewster shortly before half-time.
After the break Skerla sent a free header over the bar but the Pars could not find an equaliser.
With four minutes left home substitute Derek Young, a former Aberdeen player, volleyed wide.