The Green Brigade unveiled a banner before the game inspired by Conor McGregor, the mixed martial arts superstar but the fighting talk was all done on the park.

And it was Celtic’s own heavyweights who came to the fore on a night in which Brendan Rodgers’ side took a definitive step towards Champions League qualification for the second successive season.

Leigh Griffiths did not need to resort to the theatrics of tying a scarf around a post to declare himself; his performance in this game showed that he has firmly arrived at this level. There was a maturity in his play, an intelligence to the way he set up the third, teed up the fourth and then claimed the fifth.

It was Griffiths who led the line to floor Astana, to leave the Kazahstans without a hope ahead of the second leg next week. The forward deserved his goal in the latter stages, although a deflection will mean that it is Igor Shitov who takes the credit for a goal that came long after this game was finished as a contest.

It is not just the considerable bounty that waits now - a bounty that will surely work in the club's favour as they head into the final stages of the transfer window - but the prestige that comes with Europe's main names on the card this autumn.

And while the Hoops will never go head-to-head in the transfer market with any of the big-hitters, they pack a decent punch of their own when they are in the kind of mood they were in last night.

They were inspired, they were clever and they got the rub of the green when they needed it. Rodgers has created a spirit and an energy within the squad that gives them hope regardless of just who might calling when the music cranks up for real.

And if Griffiths deserved to take the plaudits on a night when he worked his socks off, so too did Scott Sinclair.

Sinclair has toiled for the kind of form of last season in the early weeks of the campaign but he floored Astana with a goal either side of the interval. Given the magnitude of this victory, no-one will see the Kazakhstans get off the canvas.

Sinclair was the main draw for Celtic as an invincible treble was claimed last year and on this evidence, on a night when Celtic Park was alive with all the promise of possibility, he showed again just what he offers.

The dcadly pace, the clinical eye in front of goal, Now, with the unique delights of Champions League football coming around again, he will be expected to deliver.

In some ways Astana were the architects of their own downfall with their fate sealed in the opening half; Evgeni Postnikov’s lunging, desperate foot that couldn’t keep out Tom Rogic’s crucial opening goal while Sinclair’s second came from a fortuitous break of the ball in the middle of the park.

The gloves were off early on - almost literally in Scott Brown’s case with the Hoops skipper booked for a dunt on Patrick Twumasi in the opening half – but if ever there was a night when Brendan Rodgers’ men needed to have the stomach for the fight, this was it.

It was Brown, though, who cognisant of the need for calmness in an opening half hour in which Astana threatened to pass their way through Celtic.

Comfortable on the ball, fast in attack and clever in possession, Celtic knew they were in a game in that opening period.

The precarious nature of these games and the tightrope that is walked meant that even as Celtic headed into the break with a 2-0 lead to protect, there was still a palpable tension around the ground.

There were a few around the stadium who will have felt their pulse quicken at the sight of Craig Gordon stopping to head away a loose ball outside his area after Nir Bitton was left frantically back-pedalling after a long ball forward.

Which is what made the second half display so impressive as Celtic blew their visitors away with an approach, inspired by Griffiths, that was as calm as it was effective.

And yet, there was a maturity in the performance too. There would have been an understandable element of the support keen to see a swashbuckling second period as Celtic looked for the killer blow to really put the out of Astana’s reach but it would have left them dangerously open to a counter-attack.

Rogic was clattered in the build-up to the third, to such an extent that he asked who scored the goal as he wandered off the pitch. It was Astana, however, who will be nursing a sizeable headache this morning.

It was how Celtic finished Astana off that was of particular note. They ramped it up when they needed to, increasing the tempo to such an extent that the delivered a filleting which left their visitors longing for the whistle way before it sounded.

Griffiths was the architect of the third, Sinclair the executor and from there on Astana were weary and beleaguered.

Scenting blood, Celtic knew they had another in them.

The fourth came, a fifth came and it was Rodgers who finished the night with both fists high in the air in triumph.