A decade and a day later, the same man led his Hoops heroes to the group stage – and the £21million windfall which comes with it – in emphatic style when they defeated Helsingborgs 2-0 to qualify 4-0 on aggregate.
By the time the draw takes place in Monte Carlo around tea time tonight, Lennon and his players will have come to terms with what they have achieved.
For now, it is probably still a heady mixture of anticipation and relief which is coursing through their pulsating veins.
The second leg of their play- off tie against the Swedes was not a night to enjoy – it was one to survive.
From his own bitter experience of Basel, when Celtic went into the second leg of their play-off with the Swiss side leading 3-l only to go out on away goals, Lennon knows only too well how much of a blow to the solar plexus being knocked out when within smelling distance of the group stage can be.
Of course, that Celtic team bounced back to embark on their run to the Uefa Cup final in Seville nine months later.
However, while the parachute to the Europa League was available to Scott Brown, Gary Hooper and Co, it would have been very much a consolation prize.
The pomp and circumstance of the Champions League is where this young, ambitious group of players want to perform, and now they have earned the right and the chance.
It was appropriate that the skies over Celtic Park were storm laden, as this was the moment the thunder did return.
The loudest clap came when Gary Hooper scored 30 minutes into the game, signifying that Helsingborgs' only lifeline – to grab the first goal and rattle Celtic's nerve – was gone.
The fact the striker initially appeared to be offside when he shot in off a post from six yards mattered not a jot to the home support.
Georgios Samaras, so often a hero on European occasions, and again this time, deserved a special commendation for his part in the goal.
When Scott Brown's errant shot from outside the area landed at the Greek enigma's feet, he had the composure and intelligence to square to Hooper, who needed no second invitation to shoot.
The tie was effectively over, and when Victor Wanyama headed home from a Kris Commons cross after a short corner three minutes from time, it merely emphasised how comfortable Celtic's passage to the group stage had been.
The substantial presence of the Kenyan – suspended for the first leg, and sorely missed in the difficult first half in Sweden – proved to be a massive barrier to all Helsingborgs' hopes, long before his goal.
On the odd occasion he was circumvented, Kelvin Wilson – in for the injured Thomas Rogne and having probably his best game for the club – was ready and willing to snuff out any possible danger with tackles and headers.
It must have been demoralising for the Helsingborgs players to know that, even if they did get past this strong spine, the hero of the first leg, Fraser Forster, was waiting to keep them out.
He reminded everyone of this with a full-length save from Jere Uronne free kick five minutes after the break as the visitors tried to salvage something from the night.
Samaras – given a huge ovation when replaced by Tony Watt with 20 minutes to go – Wanyama, Wilson and Forster were ably supported by team-mates who chased, closed down, blocked – and won.
James Forrest hit a post late on, while Brown had a good shot saved, and Watt was thwarted with the rebound before Wanyama's counter.
But it's doubtful if there has been a more important goal scored by Celtic in the past decade than the one Hooper dispatched, and the effect was to allow the supporters present to enjoy the occasion, their pre-match nerves removed by the rippling of the net.
Swedish spirit sunk in tandem with Celtic's rising, and another important milestone in the development of this team, collectively and individually, has been reached and passed.
Lennon, too, will look back on a massive night in his own managerial career, which started with a damaging defeat in this competition in Braga two years ago.
His progress since then has been matched and mirrored by his team. Now, even greater tests lie in wait, the venues of which will be revealed in Monte Carlo later today.
With the golden ticket into this draw safely secured, Lennon will expect – and deserves – to see the club move in on the signing targets he has assembled.
Some, like Markus Henriksen, have already slipped away to other clubs. But, the Norwegian midfielder was not top of the priority list. That remains a dominant central defender – Wilson's display last night has not altered this – and a striker with an aerial threat.
The significant carrot of Champions League football, and the funding that comes with it, should make Lennon's strengthening quest easier.
However, with four wins from four qualifying games this season, the players he already has under his spreading wing deserve to be given a chance to show what they can do in the group stage.
Lennon might be more concerned that the likes of Wanyama will become an even bigger target for unwanted predators as he continues to show his quality at this level.
Celtic know they will be up against serious opposition in the group stage as they will be placed in the bottom pot for today's draw.
But for the first time in four years they have collected a ticket to the party, so, who cares?