Aberdeen's European run was ended by Kazakh side Kairat Almaty, despite an impressive performance from the Dons, who looked capable of progressing right up until the moment Gerard Gohou opened the scoring after 59 minutes.
Kenny McLean levelled on the night, but the Dons could not muster the second goal that would have seen them take the tie into extra-time.
McLean's first leg goal having given Aberdeen hope of progressing, they looked more than happy to go toe-to-toe with their opponents, and although the Kazakh visitors created a chance straight from the kick off, at no stage of the first half did the home side look overawed.
Goalkeeper Danny Ward was equal to 18-goal Gohou's first minute drive, and the on-loan Liverpool man was quickly off his line to deny Stanislav Lunin after a sharp counter-attack.
But the Dons quickly settled into the game, and had claims for a penalty turned down when Peter Pawlett was sent tumbling in the box after 11 minutes, following David Goodwillie's clever through-ball.
Goodwillie impressed in the lone striker role, as his hold-up play posed problems for the Kairat defence and Zarko Markovic was booked early on for a foul on the former Blackburn Rovers man.
Ukrainian international Anatoliy Tymoshchuk quickly followed into the book after bringing down Graeme Shinnie.
And Aberdeen's forward momentum continued as Jonny Hayes found space on the edge of the area to flash a left-foot shot narrowly wide of the target, with Vladimir Plotnikov scrambling across his line to cover.
Mikhail Bakaev became the third Kairat man booked in the closing stages of the opening period, with Czech referee Miroslav Zelinka standing for no nonsense.
The home side carried on from where they'd left off after the restart, with Goodwillie just delaying too long after an opportunity opened up in front of him, and Niall McGinn slicing a shot wide.
However, disaster struck for the home side just before the hour mark. They tried to play out of defence after a corner, but Bakaev broke up the move and saw his 20-yard shot parried well by Ward.
The goalkeeper could only look in, though, as Gohou stroked home from close range to give his side a valuable away goal.
That meant Aberdeen needed two goals even to force extra time, but to they refused to be downhearted and kept pressing forward, throwing on Adam Rooney in attack midway through the second half.
Goalkeeper Plotnikov was equal to Shay Logan's powerful strike two minutes later, but the 20,317-strong crowd were unhappy with his perceived play-acting having made the save, and there were further jeers when Gohou went down soon after.
The goalscorer had missed the first leg through injury and was replaced by Djordje Despotovic, so perhaps there was more credence to his injury.
There were further changes for both sides as the match entered the final 10 minutes, Willo Flood and Paul Quinn replacing Hayes and Goodwillie for the Dons, while midfielder Isael made way for Serginho for Kairat.
The Brazilian crashed a shot off the bar with his first touch, but within a minute the game was level on the night, as McLean turned home McGinn's cross at the back post.
But it was not enough to maintain what has been an excellent foray into Europe for Derek McInnes and his men, despite Quinn's last-gasp header forcing an excellent, full-stretch save from Plotnikov.