There are two ways of looking back at this match. Either it offered the perfect antidote to the theory that Celtic will have everything their own way in this season's Scottish Premier League, or it proved precisely that.

For concerted spells, the reigning SPL champions visibly toiled against an Aberdeen side who could reasonably argue they did not deserve to lose. Yet despite that, and Celtic giving the impression in spells that they were not particularly bothered about winning, Kris Commons ensured the title defence began with a victory.

Commons may take the credit for that scoring intervention, 11 minutes from time, but the role played by Jamie Langfield must be acknowledged. Aberdeen's goalkeeper somehow allowed what looked like a perfectly routine angled shot from a short corner to slip right through his body at the near post. It was a horrendous error – from a player who has been known by the nickname of "Clangers" in the past – and one which undid Aberdeen's earlier fine work. Even Commons looked embarrassed at claiming the goal.

"I would never criticise one individual," said the Aberdeen manager, Craig Brown, afterwards. "I would criticise the team for not responding appropriately to a short corner. They had clear instructions and they switched off momentarily. You cannot do that at this level. Up until then, I felt the least we would get was a draw."

Brown can take solace from the fact Aberdeen looked a vastly improved side to the one which finished ninth in the SPL last season. This time around, they should have aspirations of moving into the top half.

For Brown's opposite number at Celtic, there was relief. Occasions such as this can often prove awkward; the championship flag was unfurled before kick-off, with Celtic expected to swamp Aberdeen thereafter. The Scottish champions are also between crucial Champions League qualifying legs against HJK Helsinki.

"There was a flatness about us going forward," conceded Neil Lennon. "There was a bit of a hangover from Wednesday night but I totally understand that. We will pick up a bit more zip as we go along. Once the players find their feet they will be okay."

Of more concern to Lennon is the injury incurred by his captain, Scott Brown. The midfielder is a doubt for Wednesday's match in Helsinki because of a degenerative condition in his hip.

The pace and guile of another Celtic absentee, James Forrest, was notable during a generally turgid opening half. It took 22 minutes for a meaningful shot on target – Langfield batted away Commons' effort on that occasion. Moments later, the hosts' Georgios Samaras curled an effort wide of Langfield's upright.

Aberdeen's best chance arrived six minutes after the interval. As Celtic failed to clear a corner, Scott Vernon blazed the loose ball over the bar. Matters had returned to the realms of mundane before the winning goal came. The lively Commons played a one-two with Adam Matthews but still found himself completely unmarked. Brown is correct to identify Aberdeen's shortcomings there, but Langfield's mistake was criminal for an experienced professional.

"I don't think the keeper was on his toes to deal with anything at the near post but we will take it," Commons added. "It was a bit muggy and a bit warm and there were a lot of tired legs. We would have liked to play a bit better and we were not as free-flowing as we would like, but three points is three points."

Onwards now, for Celtic, to Finland. A much bigger prize is at stake there.