The Dons controlled the game for long periods and should have had all three points wrapped up long before the end.
However, they had to endure a nervy final ten minutes and the final whistle was greeted by the home fans with a mixture of relief and delight in the knowledge that European football will be returning to Pittodrie next season.
With only two minutes gone Dons skipper Scott Severin found the diagonal run of Peter Pawlett, who was driven wide by Ian Murray at the expense of a corner.
From the resultant corner the ball bounced around inside the area where Aberdeen had four or five efforts charged down by desperate defending.
At the other end the lightning quick flick by Steven Fletcher saw him release Lewis Stevenson, whose cross was met first time by Derek Riordan, whose left-foot effort from 12 yards screwed well wide of the upright.
Aberdeen took the lead in 14 minutes in the most bizarre of circumstances. Visiting goalkeeper Yves Makalamby was about to clear from hand when his kick ricocheted off the back of Lee Miller and drove just inside the post to give the home side an unlikely advantage.
Casual play between Javan Vidal and Pawlett allowed Fletcher to steal the ball before teeing up his strike partner Riordan, his fierce 25-yard effort was comfortably held by Jamie Langfield.
Following a lacklustre period of the game Aberdeen had a great chance to add to their earlier goal on 28 minutes.
Severin smashed in a great 25-yard shot which brought out a brilliant stop from Makalamby with the ball rebounding into the path of Pawlett, however the young striker couldn't get over the awkward bouncing ball and his effort flew tamely over.
Minutes later Aberdeen again passed up a great chance, when a deep Charlie Mulgrew corner found the head of Severin, his downward header brought a fantastic block from Makalamby.
On 31 minutes a Mulgrew corner caused all sorts of panic in the visitors' defence. A poor clearance from Murray saw the ball break to Pawlett whose shot hit a post from ten yards.
The ball broke back into the path of Sone Aluko who took a touch before crashing in a shot which looked goalbound, before being blocked by the imposing figure of Rob Jones on his goal-line.
The Dons deservedly extended their lead on 44 minutes. Aluko was clumsily barged over by John Rankin 25 yards from goal. From the free-kick the majestic left foot of Mulgrew sent his effort fly over the wall and past the despairing dive of Makalamby.
The visitors still had time to go to the other end of the park where Fletcher found Riordan, who neatly side-stepped inside Lee Mair before planting his 16-yard effort into the corner of the net.
The home side seemed content to hold what they had upon the re-start. The game therefore was mainly confined to midfield and lacked any quality with aimless passes the norm.
The closest either side came was on 63 minutes when a Miller free-kick from 22 yards was deflected just wide off Murray with Makalamby stranded.
The Dons looked to have sealed all three points in 66 minutes, Aluko released Stuart Duff who advanced into the area before cleverly pulling the ball back into the path of Miller, who with the goal at his mercy could only drive the ball against the legs of Makalamby from eight yards.
Disaster struck the visitors on 70 minutes, Murray who had earlier been booked, received a second yellow subsequent to the red card following a clash with Pawlett as they both raced after a loose ball.
Aberdeen's last chance came after 88 minutes when Souleymane Bamba needlessly handled inside the area.
However from the resultant spot-kick Aluko's weak effort was palmed away at the post by Makalamby.