The Dons came through an absolutely breathless second half in front of a raucous Pittodrie to book a trip to Baku in the Conference League play-off next Thursday, the Red Army getting plenty of entertainment - and a few scares - for their entrance money.
After the dramatic late win at Livingston last Sunday, Stephen Glass made five changes to his Aberdeen side to take on Breidablik at Pittodrie. In came Scott Brown, Ross McCrorie, Lewis Ferguson, Calvin Ramsay and Christian Ramirez, replacing Jack Gurr, Niall McGinn, Teddy Jenks, Jonny Hayes and Jay Emmanuel-Thomas in the starting XI, all of whom dropped to the bench.
Breidablik made two changes from their 3-2 first leg defeat in Iceland. Atlason and Svanthorsson replaced Sigurdarson and Steindórsson in their starting team, the latter two dropping to the bench.
The Red Army were back out in numbers at Pittodrie, bellowing their support as the game got underway. The Dons responded, Andrew Considine setting Ryan Hedges away, his cross blocked behind for a fourth minute corner. Ramsay's cross reached Considine at the back post, but nobody in red could get on the end of his knock down.
Breidablik were lively - and physical - looking to employ sweeping diagonal passes forward but Aberdeen were dealing with the threat relatively comfortably early on, neither goalkeeper having a lot to do in the opening 20 minutes.
A glimmer of a chance came on 20 minutes as a sliced clearance came looping over Hedges' head at the by-line, but he wasn't quite able to hook the ball over his head and back into the box for Ferguson. A minute later, Eyjólfsson went into the book for a late charge on Brown.
Ferguson had the game's first shot at goal on 25 minutes, firing well over the bar from out on the left, an indication of the stalemate we'd seen in the first quarter of the game.
Breidablik might have had a goal on 32 minutes, a swift passing move getting them down the pitch and ahead of the Dons' defence until McCrorie came flying across to make a vital sliding tackle to take the ball off Einarsson's toe, though the hosts would have been saved by an offside flag if needed.
Aberdeen had a golden chance to get on the scoresheet on 36 minutes. Brown stole the ball off the visitors 30 yards from goal, exchanged passes with Ferguson and then threaded the unmarked Hedges through, but from 12 yards out, he didn't get enough on his low shot, allowing Einarsson to get down and make a sharp save.
The Dons were at it now and on 39 minutes, MacKenzie's rasping shot across goal was well saved by Einarsson at full stretch after good work by Brown and then Hedges, who fed the ball out to the youngster. Aberdeen worked it back in, Ramsay's cross into the near post deflected across goal and wide by Hedges from a tight angle.
Ramirez was next in on goal on 42 minutes, lovely one touch football from Aberdeen around halfway ending with Ferguson playing a lovely pass to get the centre-forward beyond the defence. Looking to shape the ball around the goalkeeper, Einarsson read his intentions well and made another good save. The half-time whistle was the next action, to the frustration of the home side who were just beginning to get the bit between their teeth.
HALF-TIME: ABERDEEN 0 BREIDABLIK 0
Connor McLennan and Funso Ojo were introduced after the break, McGeouch and Gallagher replaced as Aberdeen went to four at the back. It proved inspirational, Ojo getting on the ball down the left, weaving his way into the penalty area, then showing great persistence to get to the by-line, skipping past another challenge and then pulling the ball back into the six yard box where Hedges was poaching to stab the ball in for 1-0.
The visitors were losing their discipline now, Vilhjálmsson into the book on 49 minutes for a late swipe on Ferguson. Ferguson then should have sealed things two minutes later. It came from more great work from Ojo, winning the ball on the left and galloping forward to square for Hedges. His backheel found Ferguson but his shot from a dozen yards out arced just wide of goal.
Breidablik made a double change on 55 minutes, Steindórsson and Sigurdarson, omitted at the start, back on the pitch in place of Atlason and Sigurjónsson. The visitors threatened a minute later, Einarsson putting in a dangerous ball on the right flank, Vilhjálmsson getting up highest at the back post but glancing his header wide.
Aberdeen were pushing again on 57 minutes, MacKenzie and McLennan working well down the left, Hedges unable to quite work an opening when it came to him in the penalty area.
Two minutes later, against the run of play, the visitors were back in it, a break down their right allowing Einarsson to pick out Eyjólfsson on the edge of the penalty area. Given too much space, he wrapped his boot around the ball to stick it in the far corner with Joe Lewis helpless, putting the tie back in the balance.
Gunnlaugsson was the third booking of the night for a crude hack on MacKenzie on the hour as the game was getting increasingly frantic.
McLennan wasn't so far away from goal on 63 minutes, clipping a shot just over the bar from the edge of the area after more good approach work from Ojo and Hedges. A minute later, it was Hedges in on goal, Ramirez holding the ball up well and feeding McLennan. He found Hedges but his low effort at sweeping the ball into the goal was foiled by the goalkeeper.
Lewis was in decisive action on 65 minutes. Ferguson was robbed 25 yards out and from there, Breidablik got Svanthorsson in on goal, but Lewis came tearing off his line to narrow the angle and make a super save, Vilhjálmsson then slashing at the loose ball and putting it into the crowd. The game was stretched now, bouncing from one end to the other, incidents thrown up at every turn.
Nerves were settled again on 70, Hedges guiding a glorious finish around the defender, and across goal and into the side netting from 20 yards out to make it 2-1. There'd been more fine play from Ojo and then Ramirez in the build up to the goal, the number nine cushioning Ojo's ball into him back into the run of the Welsh international to score.
No time for relaxing though for within a minute, Vilhjálmsson was in on goal once again, only to balloon the ball over the bar, to the collective and audible relief of Pittodrie.
McLennan had another great chance on 75 minutes. He did all the hard work with a great first touch from a ball over the top but as he chased in on goal, his finish didn't match up to that quality, giving Einarsson the opportunity to smother his shot.
Breidablik were cutting frustrated figures now and another poor foul, this time on MacKenzie, had Einarsson in the book on 77 minutes. Svanthorsson was in on goal again almost immediately but inexplicably, he chose to cross rather than shoot and the Dons were able to clear the ball behind.
Hayes and Emmanuel-Thomas were the Dons' next changes on 79 minutes, Ramirez booked for taking too long to go off, MacKenzie also replaced, still limping from that earlier challenge.
Considine wasn't far away from making it three on 81 minutes, Ramsay spearing a right-wing free-kick across the area to the back post, the defender's header back across goal flashing wide.
Five minutes left and the visitors won a free-kick on the right edge of the box. Gunnlaugsson delivered a brilliant ball through the box, Emmanuel-Thomas getting a crucial touch to put the ball away to safety.
Three minutes left and the visitors made two last ditch changes to try to rescue things, Gudbjargarson and Margeirsson on for Svanthorsson and Einarsson, while the Dons brought on Jenks for goalscorer Hedges. Emmanuel-Thomas and Jenks both had pot shots at goal from distance as the game edge towards its conclusion, then Emmanuel-Thomas' clever ball through the six yard box was just inches ahead of Ojo.
But the Dons had done the job, securing their passage to a play-off with Qarabag FK on an emotional evening back in the old stadium.