A day after Celtic officially recognised the 125th anniversary of their foundation, the class of 2012 delivered one of the finest European results in the club's history.

Neil Lennon's understrength team displayed wonderful tenacity and ruthlessness to see off Barcelona, even if some seriously edgy moments were triggered by a stoppage time Lionel Messi goal. Few could legitimately begrudge Celtic their success, which also offers a timely boost to the standing of Scottish football in otherwise troubled times.

Lennon enjoyed a decorated playing spell in green and white but, for Celtic's manager, this occasion will go down as a career highlight. It also illustrated the Northern Irishman's growing status in the dugout.

Celtic have beaten illustrious opposition on their home patch before, including Barcelona, but the current status of Tito Vilanova's side renders this especially significant. Afterwards, the Barcelona manager rued his players' inability to claim the game's first goal.

In the midst of epic celebrations in Glasgow's East End, the significance of this win in a Champions League context was almost forgotten. Celtic are now on the verge of the last 16.

The Scottish side had to ensure the hope did not kill them, if such positive sentiment could ever precede a meeting with the best club side of the modern era, if not all time.

Celtic received legitimate praise for their showing in the Camp Nou a fortnight ago, where it took an injury-time Jordi Alba goal to secure Barcelona's 100th Champions League win. Lennon had been keen to point out in the build-up to this game that Barça's potency is not blunted when they play away from home.

Celtic had also suffered the misfortune of injuries to key players. As expected, Gary Hooper – Lennon's most prolific striker – and Emilio Izaguirre sat out this match but there was surprise about the absence of the captain Scott Brown, who had been struck down by a virus.

The visitors' first opportunity fell to the irrepressible Messi, who scooped over the crossbar from an Alba cross in the eighth minute. Generally, though, Lennon would have been content with Celtic's opening to the game amid a typically rousing atmosphere; Victor Wanyama was about to intensify that.

As was the case in the match in Catalonia, a Charlie Mulgrew set play created sufficient trouble in the Barcelona defence to force a Celtic goal.

From Mulgrew's corner, Wanyama bulleted a fierce header past Victor Valdés. Lennon later admitted he had spotted a Barcelona weakness at defending corner kicks elsewhere in their Group G campaign.

The goal was fitting reward for Wanyama, whose fine midfield play had earned Celtic rare possession in the opponents' last third. He was to enjoy an outstanding night's work in front of scouts from England, including Manchester United.

Barça's attempts at a response, as intricate and patient as ever, found admirable resistance among the Celtic back line. In Messi's case, he clipped Fraser Forster's bar from 16 yards. Alexis Sánchez was the next to threaten, with a shot which bounced wide off Forster's left-hand post. Celtic, though, managed to survive until the brief respite afforded by the half-time whistle.

Barcelona stepped up their efforts at claiming an equaliser after the interval. Messi tested Forster with a curling effort from 18 yards, before the Celtic goalkeeper produced a fine double block to deny Sánchez.

By the hour mark, Barcelona were territorially dominant without their hosts looking overly perturbed or panicked. That, of course, was to Celtic's enormous credit given the savage beatings Barça have dished out to teams in similar scenarios.

A glimpse at spare resource offered the La Liga team hope. Vilanova had the ability to bring on David Villa and Cesc Fábregas, as he duly did. Lennon, by contrast, had four youngsters among his six outfield substitutes.

Still, Vilanova was lucky his team were not reduced to 10 men as early as the 68th minute. Alex Song, already on a booking, clattered through the back of Miku, with the referee showing notable generosity to the former Arsenal man.

Forster's finest save of the night was still to come. The England squad member produced a wonderful, diving one-handed stop to frustrate Messi again.

This time, it was Celtic who were to close out the match in its dying stages. Straight from a Forster kick out, Xavi Hernández clean missed his attempt at playing the ball back into the Celtic half. In what represented the stuff of fairytales, the 18-year-old Tony Watt, a £50,000 signing from Airdrie, raced through and lashed beyond Valdés.

Barça hope arrived from Messi, who scored a rebound from close range. Yet Celtic could not and would not be denied. The timing of their jubilation seemed wholly appropriate.