The Scottish champions are on the brink of elimination from the Europa League after Molde completed back-to-back victories over them to secure their own passage into the last 32 of the tournament.
The final whistle was greeted by a chorus of jeers from the home fans who had witnessed another display of shambolic defending by a team who have now conceded 13 goals in their last six European fixtures.
Remarkably, Celtic could still join Molde in the knockout stages. Despite being bottom of Group A with just two points, victories at home to Ajax and away to Fenerbahce in their remaining two fixtures would take them through. But there is little evidence to support belief that scenario could play out.
Celtic will face Ajax in three weeks’ time without Nir Bitton, sent off in the closing stages last night, and Stefan Johansen who collected his third booking of the tournament. It was a night when almost anything which could go wrong for Celtic did go wrong.
As much as his own players were the architects of their defensive downfall yet again at this level, Deila would also have felt the footballing fates were conspiring against him in the opening stages of a tumultuous contest.
Just four minutes in, Jozo Simunovic collapsed on the turf following a challenge by Tommy Hoiland. The Croatian central defender had been a doubtful starter because of an ankle injury and, after lengthy treatment, he was unable to continue.
Deila opted for Tyler Blackett, rather than the error-prone Efe Ambrose, to come off the bench to replace Simunovic alongside Dedryck Boyata in the heart of his back four.
Celtic thought they had responded to that early disruption in the best possible fashion when Nir Bitton’s shot from distance beat Molde goalkeeper Ethan Horvath and nestled in the corner of the net in the tenth minute.
But their celebrations were halted by an offside flag against Leigh Griffiths who was lurking around the six-yard box in front of Horvath.
The frustration of the home support and players intensified when Griffiths was ruled offside again two minutes later, this time when he netted from close range after Horvath parried a Kris Commons shot.
Celtic had at least opened up firmly on the front foot but it did not take long for Molde to expose the all-too-familiar vulnerability of Deila’s team at the other end of the pitch.
There was a let-off for the hosts when Hoiland was allowed to race clear on goal, only a poor touch from the Molde striker denying him a clear shooting chance.
But the visitors were not so wasteful when presented with their next opportunity in the 21st minute. It was a horrible moment for Blackett as the on-loan Manchester United player sent a defensive header tamely into the path of Mohamed Elyounoussi.
The forward had time to steady himself on the edge of the box and guide a curling right-foot shot beyond Craig Gordon’s left hand and into the corner of the net.
In a contest which was compelling to watch, as much for the haphazard nature of both teams’ play as for any great quality on view, Celtic’s response was frantic and brought them an equaliser five minutes later.
Kieran Tierney, preferred to Emilio Izaguirre at left-back, hoisted in a good cross which Vegard Forren was unable to clear properly.
The ball fell to Bitton whose 25-yard shot was not cleanly struck, but the ball was diverted by Commons’ instinctive flick beyond the wrong-footed Horvath.
A shocking error by Horvath should have led to Celtic taking the lead in the 32nd minute, his poor kick-out going straight to Tom Rogic.
The Australian was unable to capitalise, though, his shot parried by the scrambling ’keeper. The ball broke to Commons whose shot was blocked on the line by Daniel Hestad.
If that was an heroic contribution to his team’s cause by Molde captain Hestad, the veteran midfielder bettered it when he put them 2-1 in front five minutes later.
It was another calamity at the back for Celtic as Elyounoussi was allowed to muscle his way to the byeline on the right-hand side of the penalty area.
His lofted pass to the far post found 40-year-old Hestad stretching his right boot beyond the unconvincing challenge of Blackett to force the ball home from close range.
Celtic were forced into another change at half-time, Commons failing to reappear for the second half as he was replaced by James Forrest.
Tierney forced Horvath into a smart save following a positive run and shot by the teenager but Molde continued to look likely to inflict damage with every counter-attack. Ole Gunnar Solskjaer introduced Ola Kamara, so dangerous in Norway two weeks ago, for Hoiland to refresh his team’s attacking threat.
Mikael Lustig, captain again for Celtic in the absence of the injured Scott Brown, thought he had dragged his team level when he met a Stuart Armstrong cross with a sweet header but he was denied by a brilliant reaction save by the erratic Horvath.
Celtic came close again from the resulting corner kick, whipped in from the right by Griffiths, when Bitton saw his close range effort scrambled off the line.
Nothing was going right for Deila’s men and Johansen triggered a suspension when he was booked for a foul on Elyounoussi, ruling him out of the visit of Ajax. Griffiths then passed up a glorious opportunity to make it 2-2. Picked out by Johansen’s pass, Celtic’s top scorer had beaten the offside trap this time but shanked his close-range shot wide. The tale of woe continued with Bitton’s dismissal 14 minutes from time, the Israeli shown a straight red card for hauling down Kamara with the Molde substitute poised to race clear on goal.
As Molde saw out the first victory ever by a Norwegian team on Scottish soil, it all added up to another desolate night for the country’s eve- diminishing reputation in Europe.
SCORERS: Celtic - Commons (26’); Molde - Elyounoussi (21’), D.Hestad (37’)
Referee: S.Vincic (Slovenia)
CELTIC: Gordon, Lustig, Boyata, Simunovic (Blackett 9) (Ciftci 69), Tierney; Bitton, Johansen; Commons (Forrest 46), Rogic, Armstrong; Griffiths. Subs not used: Bailly, Izaguirre, Ambrose, Mackay-Steven.
MOLDE: Horvath, Linnes, Toivio, Forren, Rindaroy; Singh, D.Hestad, Hussain (Gabrielsen 90+4); Mostrom (E.Hestad 62), Hoiland (Kamara 46), Elyounoussi. Subs not used: Neydson, Berge, Flo, Agnaldo.