For much of this bizarre game it felt like Celtic were swimming underwater.

Celtic Park collectively held its breath on a night when Salzburg seemed to suck all the oxygen out of the Parkhead side’s performance. For 66 minutes Brendan Rodgers’ side held the Austrians at bay but were forever pushing against the current as wave after wave of attack kept them struggling for air.

By the time they came to the surface, relief had come from the unlikeliest of places as group whipping boys Rosenborg gave Celtic the kiss of life on a night in which they had looked dead and buried.

The draw secured by the Norwegians grants Celtic safe passage into the knockout stages of the Europa League, depsite their defeat to Salzburg.

With 9 points reaped from the group, the advancement will be remembered but the night itself was forgettable for so many reasons.

The performance was insipid and slack, Craig Gordon – who kept Celtic in the game for the entirety of the opening half – had a nightmarish role in gifting Salzburg their second goal of the night, and Ryan Christie was stretchered off in considerable pain amid fears of a fracture.

Furthermore, another fine will be in the post as one ‘fan’ clearly threw a missile as Munas Dabbur celebrated the first goal of the night.

At that point it seemed like the door was closing on European football for another season. When Gordon handed a cheap second there seemed to be an acceptance that it was time for Celtic to get their coat.

And then the loud cheer and the pause for confirmation as Rosenborg’s goal filtered through the stands. By the time Celtic pulled one back as Olivier Ntcham turned his rebounded penalty into the net - the third time in succession from three different takers that Celtic have not scored directly from the spot - the game playing out in Glasgow had become an irrelevance.

Celtic will progress now to the latter stages but there will be lessons learned not just from last night’s display but from this season’s European participation as a whole.

And with a looming transfer window about to open there will be an expectation that Rodgers will take his team into the last 32 with a stronger hand that what he holds now.

For so much of last night Celtic were overrun in the middle of the park. Edouard too struggled to hold the ball up and give the Parkhead side some relief and for the bulk of the evening the Austrian side made Celtic chase shadows.

There were just 90 seconds on the clock when Scott Sinclair set pulses racing with a decent run on the left flank. His ball inside was met by the head of James Forrest before breaking to Edouard whose opportunity was quickly snuffed out.

If there was a sense that the move would set the tone for the evening, it did not last for long. With Salzburg already through virtue of the five wins they had clocked up in group B, there was a question mark before the game over what kind of attitude they might display on a chilly winter’s night in Glasgow.

They didn’t waste too much time in showing off their will to win. Before the game had hit the 20-minute mark Salzburg had hit the underside of the bar courtesy of a looping header from Diadie Samassekou. As Celtic Park hushed the ball bounced off the line before being booted out for a corner.

An early clash of heads between Mikael Lustig and Stefan Lainer resulted in the Celtic full-back heading off to be replaced by Kristoffer Ajer, who had not played since fracturing his eye socket against Livingston. The defender's lack of sharpness was quickly exposed with the Norwegian youngster slack with a pass into perfect space outside his own box for Hannes Wolf to hungrily latch onto.

Gordon was forced quickly off his line and into a deft save as he got down to stick out his right hand and deflect the effort wide of the post. It eased the pressure, but was a stay of execution. 

Celtic’s inability to keep hold of the ball with the usually reliable exponents of that art found wanting – Tom Rogic in particular was guilty of cheaply giving the ball away – meant that Salzburg seemed to be perennially on top of them.

Forrest lifted Celtic’s spirit shortly before the break with a fabulous run and pacey ball across the six-yard line that just eluded Sinclair.

It was the Englishman’s last real involvement in the game as he made way for Scott Brown at the break as Celtic shuffled things around.

Forrest took up a more advanced role alongside Edouard but the flow was again disrupted when Christie embarked on a challenge just outside the box on Takumi Minamino. It was immediately clear from Christie’s reaction that his injury was severe as he gesticulated wildly for support from the side before being stretchered off in considerable discomfort.

Midway through the second period a delivery into the box from Lainer was met at the back post by Dabbur. Gordon got a hand to the header but could not prevent it from arching beyond him and into the net.

Within minutes Gordon pulled off another acrobatic stop from Dabbur to keep the score down but the keeper was then horribly at fault as Salzburg turned the screw.

Gordon’s throw out was intercepted by substitute Fredrik Gulbrandsen who made no mistake of making sure there was no chance of a reprieve for the stopper as buried his effort into an empty net.

Celtic tried to claw their way back into the game; Ajer stuck out a leg to try and deflect Filip Benkovic’s header into the net before Ntcham grabbed the goal back.

It was nothing to the value of Rosenborg’s 86th minute leveller.

Celtic breathe again.