Dunfermline were first to show in the attack when youngster Owen Morrison made space for a shot which was comfortably held by James Langfield.
At the other end debutant Dyron Daal passed up a great chance on seven minutes when Karim Touzani picked him out at the far post.
However, rather than knocking his header across the area to the onrushing Darren Mackie and John Stewart, his effort was easily collected by Dorus de Vries in the visitors' goal.
Aberdeen had loud appeals for a penalty on 13 minutes turned down by referee Eddie Smith when Mackie tumbled inside the area under the challenge of Labonte.
Aberdeen were forced into an early change in 20 minutes when the injured Touzani had to be replaced by Andrew Considine.
On 33 minutes poor defending by Considine allowed Andy Tod in, but the big striker screwed his effort wide of target with the goal at his mercy.
Scott Wilson came to the visitors' rescue on 35 minutes when Stewart stole the ball away from Souleymane Bamba and advanced down on goal, however the Dunfermline centre-back got back brilliantly and charged down the young striker's effort.
With the first half coming to a close Dons striker Daal missed a superb chance on 43 minutes. Severin's ball into the area was brilliantly dummied by Barry Nicholson, falling to the debutant seven yards out, but his wild swipe at the ball screwed well off target.
Dunfermline started the second half brightly as Langfield saved well from Darren Young's downward header following a good cross by youngster Morrison.
At the other end, De Vries had to look lively on 59 minutes getting down smartly to hold a crisp Mackie 20-yard effort following a neat Daal lay-off.
Aberdeen finally took the lead on 67 minutes when a long diagonal ball into the area from Chris Clark was missed by the visitors' centre-backs allowing Severin to steal in at the far post and knock his header past the advancing goalkeeper.
Severin almost doubled his side's lead when the turned neatly on to a Foster cross before smashing in a tremendous shot from 12 yards which De Vries miraculously blocked.
As Aberdeen sat back they nearly conceded an unlikely equaliser in 81 minutes. A Young free-kick into the area found the head of Bamba, the ball broke back to Mason whose snatched effort from eight yards thumped into the ground and bounced over the crossbar.
With the home fans becoming increasingly anxious as their side continued to defend too deeply they again nearly paid the price on 84 minutes. Tod got ahead of Russell Anderson and nodded a Morrison cross just wide of the upright with Langfield scrambling across in goal.