Last Thursday night a lot of people thought Zenit St Petersburg turning up at Celtic Park and winning was simply a formality.
Well, the Celtic players had something to say about that and produced their most complete performance for many a month.
Celtic Park’s incredible atmosphere has frequently inspired the players in the past and yet again it didn’t disappoint and neither did the team.
There were lots of questions asked of Brendan Rodgers and his squad ahead of the supposed impossible task against the Russians, but they answered their doubters in style.
Brendan got his team selection spot on, irrespective of what some people thought.
The balance was right in the team and he gave up a bit of flair with Charly Musonda and Scott Sinclair to be a bit more pragmatic with Eboue Kouassi and the match winner, Callum McGregor.
They took the game to Zenit and the Russians couldn’t cope with the intensity and quality of Celtic's play.
If I’m honest I can’t see Zenit being as poor in the second leg, so if people think the tie is over then they need to think again.
Many are blaming the two-month winter break for Zenit’s below-par performance and we will see if that’s the case on Thursday night.
As for Celtic, they will again have to conjure the kind of the solid defensive display they delivered in the first leg.
There were a lot of questions asked regarding the two central defenders and whether they could produce when it really mattered against top opposition.
Kristoffer Ajer and Jozo Simunovic came through the test with flying colours but they know they will need to repeat that level of performance on Thursday night.
Both players grew in stature as the game went on and they kept it simple. They didn’t complicate the art of defending or take any risks and it helped their self-belief.
That will have given them the jolt of confidence that they needed, but also what their manager needed to realistically think they can finish the job off in St Petersburg.
Celtic will expect to be under the cosh at times, but having that ability to counter punch back will be vital or it will be a long night at the impressive Krestovsky Stadium.
Goalscorer McGregor’s all-action performance will need to be replicated, as will that of Moussa Dembele, who really took on responsibility as the lone striker and carried his team forward.
There’s no doubt Celtic's season will be defined by the outcome of the result.
They have already won the League Cup, they look likely to win the league and are favourites for the Scottish Cup, so advancing in the Europa League could galvanise the club even more and show progress for this bunch of players.
It won’t be easy, you can guarantee that, but strong minds, resilient defending and a clinical attacking threat are the vital components for Celtic.
Don’t write them off just yet, you do so at your peril.