THERE is a simple equation beloved of those who investigate the finances of football.

It protests that football success is directly proportionate with the sums spent on transfers and wages. Those observers, in contrast, who have studied the Moneyball theory in baseball whisper humbly that there is value to be had when prudent scouts gauge talent and pray for potential.

Spartak Moscow have taken the first route. They have sprayed millions on such as Rafael Carioca, Emmanuel Emenike, Kim Kallstrom and Aiden McGeady. The last, of course, was – at £10m – Celtic's biggest sale, yet the Irish internationalist, hampered by a knee knock, was only on the bench last night with his contribution restricted to the final half hour of the match.

Celtic, instead, have scoured Belgian football, travelled to Scunthorpe, waited for Bosmans from Nottingham Forest, Aberdeen and Cardiff City. It is a policy that has paid dividends.

The two sides of the financial argument went about their business at Celtic Park last night. The home side prevailed gloriously and dramatically but Spartak were already out of the competition before they flew into Glasgow. Their millions must now be thrown at lifting them above halfway in the Russian league. They are the Manchester City of Group G. The English champions exited the Champions League this week with the lowest points tally for an English club, eclipsing the previous record which was set by Blackburn Rovers in 1995-96. Spartak's budget, one that would have satisfied Nasa in the 1960s, gained three points in this campaign.

It has not been difficult to discern the small flaw in a cunning plan devised by the boffins in Moscow. It concerns the defence budget. Before last night, Spartak had shipped 12 goals in the Champions League group stages. There is no argument about what that figure constitutes. In terms of Mr Micawber, the net result of such profligacy is misery. Moscow spent £4m on Juan Manuel Insaurralde, an Argentinian defender who could cruelly be described as a part-time player. This designation is in tribute to his propensity for being sent off – as against Celtic in Moscow and Zenit St Petersburg last week – and his facility for switching off like a two-bob torch.

There was much to ponder in his interaction with a Georgios Samaras pass. The Greek is at Celtic because ostensibly he was not good enough for Manchester City, and that was before the sheikhs threw money down the very deep well at the Etihad Stadium. Yet he has been highly influential in this campaign and was, frankly, inspirational last night. His pass that led to the goal, though, was inaccurate but Insaurralde was incompetent, fluffing a clearance. Gary Hooper, all of a couple of million from Scunthorpe United, finished with the sort of certainty that will ensure he matches the McGeady price tag when he inevitably leaves Celtic Park.

So far, so good. However, top-class players sometimes forget that the match means nothing in terms of progress, that it can be enticing to curl up and hide on a cold night in Glasgow.

Spartak had both accomplished and willing performers. Kallstrom had already given an indication of his undoubted class with some clever promptings and a swept shot past a post, all in contrast to the two challenges that eventually led to his dismissal. Emmanuel Emenike, too, was threatening in the early stages and the £9m Nigerian inevitably delivered a wounding blow. His almost casual dismissal of Biram Kayal on the edge of the box was followed by a slick pass to Ari, who chipped the ball into the net for the equaliser.

The silence around Celtic Park was followed by a roar of defiance, but this was a Celtic side already playing to their limits. This was the Scottish champions summoning every resource, galloping every yard and fighting for every ball. Mikael Lustig and Emilio Izaguirre, who both cost the football equivalent of a used Lada, drove up the wings with vim if only occasional finesse.

But how to transform the base metal of honest effort into the gold of a breakthrough goal? This alchemy was beyond Scott Brown. He shimmied into the area but his left-foot shot was as weak as the economy. And then there was Sammy, a study in neurotic energy. A clipped shot off the post, a sprint and a cross that was cleared, a glide across the area that ended just outside Dalmarnock.

Neil Lennon was now in the position of the impoverished gambler. He looked at his hand, and the events at Camp Nou, and decided to go all in. Kayal was withdrawn, Lassad Nouioui thrown on and the bugles sounded for one last, desperate charge. What followed was an invigorating tune of glory. Sammy went down, Kris Commons stepped up and despatched the penalty.

There were agonising minutes to endure for the home support. But finally the Spartak millionaires stood frozen, unbelieving on the Parkhead turf.

The bottom line is that Celtic are still in the Champions League. Sometimes, just sometimes it is not all about the money.