The post-mortem into why the club failed to win away from home in the group stages of the competition at the 18th attempt is under way after a dramatic night in the Energi Nord Arena.

The Scottish champions dominated almost from the first whistle but ultimately surrendered the lead given to them by Barry Robson's diving header after 53 minutes.

The first unexpected blow came in the 73rd minute when Caca drew his side level with a drive from 25 yards which deflected off captain Stephen McManus before looping over Artur Boruc.

More misery followed when Gary Caldwell put through his own goal with only three minutes remaining to deny Gordon Strachan's side even the consolation of a UEFA Cup place and leaving the Parkhead club to re-focus on the three trophies available to them at home.

Celtic have a four-point lead over Rangers at the top of the Clydesdale Bank Premier League.

The champions will play Dundee United in the semi-final of the Co-operative Insurance Cup in the new year, when they will also begin their quest to secure the Homecoming Scottish Cup.

A defiant Samaras told PA Sport the Parkhead side will devote all their attention to domestic success, starting with Saturday's SPL clash against Inverness at Celtic Park.

"I think everybody is disappointed that we are out of Europe," the Greece international said.

"We were a bit unlucky but that's football.

"We didn't create a lot of chances, we didn't have the final ball but in the end it was two unlucky situations and we were back home.

"The only thing we can do is keep our heads up and go out and win the SPL game on Saturday.

"We have to focus on the three trophies that we have in Scotland and, yes, for sure, we have the squad to win them all."