THERE are life-affirming European nights at Parkhead and there are others when every supporter feels as if they have aged a decade in 90 minutes.

The end result can be just as sweet either way. What agonies Celtic went through last night, what torture and stress they suffered at the gates of the promised land, before pushing through.

The Champions League took its pound of flesh in an excruciatingly tense end to the Group G campaign in which they were heading out of the tournament, then through, then out and finally through again. Only when it was all over could they let the elation wash over them. They had achieved something special.

They did their part of the job by beating a decent Spartak Moscow team and had to wait until the bitter end, hoping that Benfica would not overtake them with a late winner in Barcelona. That goal never came, so Kris Commons's 80th-minute penalty was precious. It meant Celtic are in the last 16 of the Champions League, the first Scottish club to take 10 points from a group campaign. The adventure continues. On December 20 they will learn who they face when the competition resumes at the end of February.

The club's 150th game in the European Cup will long be remembered for what it delivered, if not for the match itself. Gary Hooper put them ahead and Ari equalised before half-time. Celtic were stronger in the second half and Commons' penalty won it, but Parkhead was distracted by events in Barcelona. They craved a home win there, but for once the Catalans misfired. Some cruel misinformation swept around Parkhead that Barca had scored in the 54th minute and the stands roared. But no, that would have been too easy.

There were long spells of the night when this wasn't the thunderous, pulsating Parkhead. The place was packed again, of course, but the stadium was twitchy and uncertain. The volume didn't reach the sustained levels it had when Barcelona were beaten here, although the old place did shake again when Hooper gave Celtic the lead. For the most part the supporters had two reasons to be jittery: they couldn't be comfortable about what was happening between Benfica and Barcelona; nor could they relax given the questions being asked of their team by Spartak.

The Russians supposedly arrived in disarray, demoralised by poor results and the sacking of coach Unai Emery. Their campaign was over last night, whatever the score. Yet they imposed themselves on Parkhead, having by far the majority of the first-half possession and planting the game largely in Celtic's half. They found little pockets of space in front of the Celtic back four and forced Biram Kayal and Scott Brown into gruelling shifts. Kayal was surprisingly preferred to Joe Ledley, who was a substitute, as Neil Lennon thought him better suited to filling the anchor role vacated by the suspended Victor Wanyama.

When Celtic took the lead, it was from a counter-attack. The chance actually seemed to have gone when Georgios Samaras overhit a diagnonal pass to Hooper but fate smiled on Celtic. Central defender Juan Insaurralde made a hash of intercepting the ball and merely ushered it into the path of Hooper. The rest was superb. The striker instantly rifled the ball low past Sergei Pesyakov.

Commons was bright for Celtic, Kim Kallstrom and Emmanuel Emenike equally so for the Russians, yet there were few clear openings or incidents. Emenike did screw one shot well wide, Commons fizzed one just past the post and Brown finished weakly after fine work by Mikael Lustig, but it was a poor return given both defences looked hesitant and prone to mistakes.

Spartak deservedly equalised six minutes before half-time and it was down to poor defending from Celtic. Kayal's challenge on Emenike was far too soft and the big striker brushed him off before slipping a lovely pass to Ari, who had the time and technique to chip Fraser Forster despite Kelvin Wilson's desperate attempt to clear under the bar. Spartak, who kept Aiden McGeady on the bench until the final half hour, were worth that and predictably it punctured the mood around Parkhead.

McGeady came on, to a warm reception, after Celtic had made a more forceful start to the second half, almost scoring when Samaras' terrific volley brushed the outside of the post, and then when Efe Ambrose met Commons' corner with a header into the side-netting. In truth, it didn't look like Celtic's improvement would be rewarded but 10 minutes from time they got a break. Marek Suchy's push on Samaras didn't amount to much but it put him down, and German referee Felix Brych called it as a penalty. Commons was utterly nerveless, smashing it straight down the middle and in off the underside of the crossbar.

Both sides finished with 10 men after Kallstrom collected a second booking for a late foul on Commons, resulting in the latter being stretchered off. Celtic had already made three substitutions so Spartak's red was no disadvantage to them. There was too little time left for it to matter. Soon the two final whistles sounded – in Glasgow and Barcelona – and Celtic exploded.