Barely had the final whistle sounded and Lennon was up on his feet, bounding up and down on the spot and punching the air repeatedly. He probably didn't celebrate the Champions League win over Barcelona with such vigour or intensity.
This, on the surface, was no more than a good result against decent opposition but Lennon appreciated the wider significance. This was Celtic's last game before the winter break and the victory ensured they went into the shutdown in a contented state of mind, having constructed a nine-point lead at the top of the Clydesdale Bank Premier League and with a last-16 Champions League tie to also look forward to.
Nobody wants to go on holiday with something nagging at the back of their mind and the weight off Celtic's shoulders was clear. Within hours of leaving Celtic Park, Biram Kayal was tweeting pictures of himself and Georgios Samaras at a London airport, the pair looking relaxed before presumably heading for a few days at home. It is difficult to imagine the Celtic players having that same demob happy feeling had Motherwell won – as they threatened to do when they were awarded, but missed, a penalty 15 minutes from time – and closed the gap at the top to just three points.
The re-introduction of the winter break after a decade's absence has been widely welcomed, but Lennon and his players would have found it harder to get comfortable on their sun loungers if they had signed off with a second consecutive loss, their defence of the title suddenly under threat.
A nine-point advantage with just 17 games remaining now seems insurmountable, even given Celtic's inconsistent form this season. It allows Lennon to devote most of his attention to other matters, most notably the Champions League tie against Juventus and to improving his squad. Celtic will head to Marbella next week for a winter training camp but Lennon won't linger too long, the manager is already planning to attend games in England and elsewhere to look at possible signing targets. He has spoken of adding balance to his side by signing a natural left-sided player, while perhaps adding one or two others to fill other gaps.
Celtic already have by far the most well-stocked squad in Scottish football. Missing from the victory over Motherwell were James Forrest, Scott Brown, Joe Ledley, and Anthony Stokes, and they undoubtedly have a strong enough group to see off any lingering threat to their title defence. Celtic, though, remain in four competitions going into the latter part of the season and Lennon may feel he needs extra bodies just to keep going on all fronts.
Already he is resigned to losing Efe Ambrose to the Africa Cup of Nations, which runs until February 10, while the decision yesterday to uphold the two-game suspension handed out to Kelvin Wilson for catching Dundee's John Baird with his elbow means Lennon will be without his first-choice central defensive partnership for the first two games back after the break, the latter the Scottish Communities League Cup semi-final against St Mirren. Charlie Mulgrew and Thomas Rogne would be more than able deputies but the pursuit of Rami Gershon, an Israeli internationalist, shows that Lennon would prefer to have cover for every position if possible.
Lennon has ruled out making a "marquee signing" similar to Robbie Keane's January arrival three years ago and will continue to pursue the Moneyball policy of seeking out players either overlooked or as yet undiscovered. Israel – where Kayal, Ambrose and Gershon were all spotted – is proving to be a lucrative market, and Lennon and John Park, Celtic's chief scout, have shown a willingness to travel just about anywhere if a talented player is available at the right price, the right salary demands, and the right age.
A Scottish league deprived of its keynote fixture may not be much of a selling point to potential signing targets, but the lure of a Champions League tie against Juventus – as well as the prospect of winning regular silverware – should surely make up for the absence of the Old Firm matches when it comes to selling the lure of Celtic.
Lennon must hope such perks will be enough to persuade his own players to stay as well. Gary Hooper continues to be linked with clubs down south, a move that would undoubtedly enhance his prospects of being capped by England. Hooper has scored 18 goals this season and shown he has the talent to play at a higher level, meaning Celtic will have a decision to make if they were made an offer in excess of £6m for the striker.
Celtic are under no great financial pressure, but one significant sale could enable to club to bring in three or four in the summer. It will likely be the only dilemma to trouble Lennon in the coming weeks.