The Scottish champions will head to the Swedish capital next week confident of sealing a place in the group stage after second half goals from James Forrest and Odsonne Edouard gave them a hard-earned but fully merited victory.
For Celtic manager Lennon, it was a positive start to a spell of four games in 11 days, culminating in the first Old Firm showdown of the season at Ibrox, which could set the tone for the rest of the campaign.
The restoration of Callum McGregor to his optimum role at the heart of midfield provided the platform for Celtic to eventually dominate possession and control the tempo of the game, although it was only after a sluggish opening 15 minutes that they began to exert the level of control Lennon would have craved.
AIK were set up to frustrate, their 3-5-2 formation more often than not switching to a 5-3-2 which restricted the number of clear cut chances Celtic were able to carve out.
The visitors were content to wait for counter-attacking opportunities, the first of which forced an error from Jozo Simunovic at the heart of the home defence. It allowed AIK captain Henok Goitom to nip in ahead of him and get away a shot which forced Craig Gordon into an unorthodox save with his feet.
Celtic were unable to full clear the danger and when the ball was whipped back into their penalty area, Kolbeinn Sigthorsson headed wide from around eight yards.
It proved the jolt for Celtic to begin imposing themselves in their attacking third of the pitch, although an offside flag cut short home celebrations when Edouard latched onto Ryan Christie’s pass and slotted beyond Oscar Linner.
Celtic came close in the 20th minute when a delightful back-heeled pass from Christie picked out Boli Bolingoli’s overlapping run on the left of the penalty area. The Belgian left-back, again looking far more effective going forward than when forced to defend, cut the ball back into the path of Mikey Johnston whose shot was deflected narrowly wide of Linner’s left hand post.
As the hosts sought to build some momentum, the AIK goalkeeper was called into action when he threw himself to his right to turn away a powerful shot from Edouard who had held the ball up and turned brilliantly to create the opening from 20 yards.
From the resulting corner kick, whipped over by Christie, there were loud appeals for a penalty from Celtic who claimed Christopher Jullien’s header had been blocked by an AIK hand. Hungarian referee Tamas Bognar was unmoved.
While AIK rarely managed to get out of their own half, the set piece aptitude of Seb Larsson presented potential danger whenever they did. A corner from the former Arsenal midfielder caused uncertainty in the Celtic defence 10 minutes before half-time before Sigthorsson’s shot was blocked by Scott Brown.
A degree of frustration crept into Celtic’s work in the closing stages of the first half but they emerged re-energised after the break and were quickly rewarded with the breakthrough.
Linner did well to repel Celtic’s first attempt of the second half, turning over a stinging shot from McGregor, but the 22-year-old Swedish international won’t look back with any fondness on his part in Forrest’s 48th minute opener.
Bolingoli drove forward and played the ball to the edge of the penalty area where Rasmus Lindkvist mistimed his attempt to meet it before Forrest. The winger surged into space and while his shot was well struck, Linner was able to get two hands on the ball but could only help it loop over him into the net.
As Celtic looked to press home their advantage, Linner redeemed himself somewhat when he made a fine reaction save to keep out a fierce drive from Christie.
While the single goal lead would have been far from the worst outcome for Celtic, its vulnerability was illustrated when AIK managed to muster a decent spell of possession during which Gordon was relieved to clutch Nabil Bahoui’s looping header underneath his crossbar.
Celtic were soon back in command and the security of a second goal was delivered by Edouard’s sweetly struck free-kick. Daniel Granli conceded it with a clumsy foul on Johnston around 22 yards out. From a central position, Edouard swept it over the defensive wall and beyond the despairing left hand of Linner high into the corner of the net.
McGregor dragged a shot narrowly wide as Celtic continued to probe for further insurance ahead of the second leg but they will feel this is a job they are capable of seeing through.