Celtic have been consigned to the Europa League playoffs after succumbing to a 2-1 loss at the hands of AEK Athens at the Olympic Stadium for a 3-2 aggregate defeat in their Champions League third qualifying round tie.
The Scottish Premiership champions took an early lead at Parkhead a week ago, before being pegged back by their visitors when Viktor Klanaridis netted just before half time.
Konstantinos Galanopoulos was sent off after the break, but the Hoops could not make the most of the opportunity, meaning that they had to score in the second leg because of AEK's away goal.
However, Celtic made a calamitous start when sloppy defending allowed Niklas Hult to reach the byline and cut back for Brito Rodrigo Galo to poke home from close range on six minutes.
From then on, Brendan Rodgers's charges grew into the game, Tom Rogic weighing in with a 12th-minute effort from outside the box which Vasilios Barkas was able to claim.
Leigh Griffiths, Callum McGregor and Jack Hendry also contributed dangerous efforts, but Celtic could not find an equaliser come the half-time whistle.
Just four minutes after the restart, the visitors conceded again through poor defending as Hendry was beaten to the ball and Marko Livaja, unmarked in the six-yard box, headed home.
However, with 12 minutes to go, Celtic gave themselves renewed hope of progress when Scott Sinclair connected with a header at the near post from McGregor's left-wing cross and found the back of the net.
Six minutes of injury time were announced at the end of the game but despite this, the Glasgow giants could not find an equaliser, which brought an end to their Champions League journey.
Celtic will now face Spartaks Jurmala or Suduva in the Europa League playoffs, while AEK will play either Malmo or MOL Vidi in the Champions League playoffs.
AEK ATHENS (4-4-1-1): Barkas; Bakakis, Oikonomou, Lampropoulos, Hult; Galo (Albanis 82'), Saldanha, Simoes, Bakasetas (Cosic 90+1'); Livaja; Victor (Mantalos 73')
CELTIC (5-3-2): Gordon; Forrest, Lustig (Dembele 60'), Hendry, Simunovic, Tierney; McGregor, Brown, Ntcham; Griffiths, Rogic (Sinclair 76')
