TRYING to predict how a Champions League group will pan out is trickier than it sounds.

Celtic lost their opening two matches this season and it damaged them - of course it did - but the spring in everyone's step around Parkhead yesterday was evidence of repaired belief. Beating Ajax on Tuesday night amounted to a building block finally being laid down. One of these days Celtic might go through a whole campaign without winning any of their six games: but it will not be this year, and it will not be this set of players.

In 2004/05, Celtic were beaten in their first three group games and did not lose any of the remaining three. They did not make it out of that section with Barcelona, AC Milan and Shakhtar Donestsk but the yin and yang of their results proved that jumping to conclusions is not a worthwhile exercise in the Champions League. In 2007/08, Rangers beat Stuttgart, won in Lyon, then drew at home to Barcelona: they had seven points at the halfway stage. And they still had seven at the end and went out of the tournament. The group format of the Champions League, swift and compact, invites projection and extrapolation about how future fixtures will pan out, yet one of the competition's many attractions is its capacity for throwing up surprises.

At the halfway stage this season Celtic are exactly par for the course. Predictably they lost away to Milan and at home against Barcelona, and now they have three points from the "easiest" game of the whole campaign. There is no justification for using such a dismissive adjective to describe a victory over a reasonable Ajax team, but if Celtic cannot win at home against the team seeded third in the group then they are not likely to get much joy out of any of the other games.

They did so thanks to James Forrest's penalty and Biram Kayal's deflected shot. Talk of getting some overdue luck was boring and meaningless. Teams that are pressing in matches take shots which can be deflected into the net, simple as that. Celtic found that out to their cost when Christian Zapata's drive spun off Emilio Izaguirre into the net in Milan, and to their great relief when Kayal's effort was similarly rerouted off Stefano Denswil on Tuesday.

Celtic are the fourth seeds in this section yet there would be plenty of criticism and mockery coming their way, and manager Neil Lennon's, if they had taken only a tiny smattering of points from the campaign. Perhaps they will finish without adding any more, but for now the 2-1 win over Ajax has given them a foothold and left them feeling more comfortable and at ease with themselves. What they are conscious of, this season, is the possibility of delivering a poor campaign which corrodes the reputation and plaudits they earned for defeating Barcelona and reaching the last 16 in 2012/13.

Had they lost to Ajax - and even allowing for the Champions League's aforementioned capacity for surprises - the second half of the campaign would have loomed like a prolonged and joyless exercise in flogging a dead horse. "I wanted to win the game for my own reputation, the club's reputation, the players' reputations," said Lennon. "The result has given us an opportunity now to go forward in the group."

The remaining fixtures are Ajax away, AC Milan at Parkhead and finally a trip to Barcelona. "I think we can give any team a game at home," said Lennon. "Now it is really important, if we want to make the top two places, that we pick up something away from home. We are really going to look at Amsterdam and think 'can we get something there?' I saw enough in the game to suggest we can but I also saw enough in the game to suggest it is going to be really difficult."

There was as little between Celtic and Ajax - both without key players - as any 2-1 scoreline would suggest. The return game could go either way. The belief that Milan can be beaten at Parkhead is legitimate but the Italians are probably being underestimated on the back of an ordinary performance, by that great club's standards, when beating Celtic. They remain unbeaten and their knees will not be knocking at the prospect of coming to Glasgow.

Facing Barcelona at Camp Nou normally amounts to one of those fixtures a club writes off, abandon all hope ye who enter here, etc. Celtic's wish is that the Spanish champions will have won the group by the time the clubs meet in December and may give that final fixture less than their full attention. In short, none of the remaining games offer certain outcomes.

Only five of the Celtic team which started in last season's win against Barcelona were also on at kick-off against Ajax. That figure would have been higher had Kris Commons and Adam Matthews been fit, of course. Scott Brown did not play in that iconic result and is currently absent again, this time because of suspension. Celtic are appealing Uefa's decision to extend the mandatory one-game ban to three. "I'm not convinced about the wording of it [Uefa's explanation], I think we have a good case to appeal," said Lennon.

The suspension is a matter of regret for Brown, a headache for Lennon, but an opportunity for Kayal. Lennon is reluctant to partner Joe Ledley with Charlie Mulgrew at the base of midfield because both are left-footed. The Scotland internationalist has made himself indispensable and that means there is an opening for Kayal at Ledley's expense.

Injuries have taken their toll on the Israeli's career, taking much of the early shine out of his play, but Lennon purred over his performance against Ajax. "That run and shot after he scored was like him in the old days. Even the tackle on Viktor Fischer, I wasn't sure he was going to make it there. Kayal maybe three, four months ago wouldn't have done but he has got that extra pace back. He makes a great tackle and that was a turning point, it was important."

Kayal was struggling to make an impression and now he has a chance again. The description also applies to Celtic.