THE economics of the Champions League should carry a rider warning that all figures are subject to change.

Gordon Strachan, when Celtic manager, pointed out that when his side failed to qualify for the group stages he was accused of costing the club £20m. Yet when he inquired about the worth of a group-stage campaign after his side had entered it, he was surprised to find qualification had brought perhaps half that.

Strachan, of course, was making a wry point but it can be said with some certainty that Celtic are now on the brink of declaring a profit for the season on the back of one profitable night in Sweden. A two-goal lead from the match with Helsingborgs leaves Neil Lennon's side in the sort of position that causes fans to salivate in premature congratulation and will force a smile on to the collective face of the Parkhead board. In businessspeak, this was a season of challenges. They are now 90 minutes from emerging from the early-season skirmishes with a result that will transform the books.

There was a sporting bottom line, too, to the events in Helsingborg last night. Lennon will look back on the result with deep satisfaction as his side avoided defeat away in Europe for the fourth consecutive match. He may also feel vindicated about his determination to keep Fraser Forster as his goalkeeper and to persevere with Georgios Samaras.

The 24-year-old Englishman was superb last night. He was called upon to be spectacular on two occasions, when blocking Alejandro Bedoya's shot with his feet and when stopping Thomas Sorum's effort. However, he was imposing throughout.

It is instructive to remember that Forster instilled doubts rather than security in his early days at Celtic Park. His decision-making could be poor, his kicking was suspect and he had the capacity to be culpable for the odd goal. Lennon and Stevie Woods, his goalkeeping coach, were steadfast in their belief that he would be a top-class custodian for the club. He was last night but, then, he has been for some time.

Celtic paid £2m for his services and the goalkeeper's actions have contributed greatly to the Champions League dividend that surely now awaits. His influence was not restricted to saves in Finland and Sweden. Forster played a major part in steering Celtic through the difficult stages of the league campaign last season, most notably saving a late penalty against Hearts when the chase of Rangers was gathering pace.

The brilliance of Forster last night was perhaps restricted to two important saves but it was his consistency that was most notable. Here was a goalkeeper who was assured, competent and spread comfort. Any resemblance with another Celtic goalkeeper who was confounded by a pass-back in Sion a year ago was surely only coincidental.

If Forster was the hero of the night, Celtic can again thank Samaras, the original and most enduring Greek crisis, for his contribution to the side's improving fortunes. Lennon has found some profit in investing his patience in a striker who can fluctuate like a dodgy stock in times of boom and bust. Samaras created the first goal with an enterprising run and deep cross that found Kris Commons, who volleyed with a pleasing certainty. He then nodded home the second with ease to ensure that Helsingborgs will have to score twice at Parkhead merely to push the tie into extra time.

These interventions were the product of Georgeous Georgios. His alter ego, Ghastly Georgios, also made the odd, very odd, appearance. Ghastly was at his best when racing clear in the second half. As he bore down on the goalkeeper, he had two choices. He could smack the ball into the net or play in a team-mate for a certain goal. Ghastly's genius was to flick the ball around the post with a bravura, wilful negligence.

Lennon would have winced but he knows that the fallibility of Samaras is what keeps the striker at Celtic. If he was consistently Georgeous he would be playing in Champions League group stages for a club that did not have to face the perilous route through the qualification process.

The most significant aspect of last night's events was not the occasional hesitancy of Celtic in defence or the lack of fluidity on occasion in midfield. It was not even the growing impression that Lennon's side, after surviving a squall, could have won more easily – Joe Ledley and Charlie Mulgrew both hitting the bar and James Forrest being denied by Par Hansson in the second half.

It was the realisation that Lennon has made some major decisions on personnel and they have proved profitable. These have all involved elements of a gamble. Samaras, famously described by Lennon as the sort of player who gets the manager the sack, was given a new contract and two touches last night have provided Celtic with a huge advantage. Forster, a goalkeeper bought for £2m, produced a performance that has surely handed the club a Champions League windfall. And Commons, routinely labelled as a player with a limited future at the club, scored his fourth goal in five matches with his strike in the second minute deserving the description of precious.

Celtic have been forced to gamble in the lower reaches of the transfer market in Champions League terms. They are now just 90 minutes away from being paid out at long odds.