NOT so much gone in 60 seconds as gone in four minutes.

But, for Celtic, the end result was the same.

The 2-1 defeat suffered at Pittodrie not only brought their 13 league-game clean sheet record to a stunning halt, it also brought their dream of completing an entire SPFL Premiership season unbeaten crashing down around their ears.

Now Neil Lennon will really find out what he has to work with, who has the stomach to get back up from this one-two to the solar plexus, and who will be content to simply coast in to the championship which requires only a delivery date.

The last time Celtic failed to win in a league game was when Dundee United left Celtic Park having fought out a 1-1 draw back on November 2 last year.

The Hoops' response was to win every league game for the next three-and-a-half months - until last night.

It's not as if the Celtic players had not been warned what danger lurked in the chilly north.

Lennon has been called many things, but prophetic is not on that list.

He did say that Celtic's unbeaten run and clean sheet record could go at the same time.

However, when the Celtic manager predicted the game at Pittodrie would be the toughest examination his side would face in the title run in, what even he did not forecast was how tough they would make it for themselves.

Sure, the Green Machine, which had steam-rollered its way to 16 wins in a row in the league, hit a major bump in the road in the form of Aberdeen, their conquerors in the William Hill Scottish Cup earlier this month.

But it was not the red of the Dons' shirts, but the card shown to Virgil van Dijk after just 12 minutes which gave them a mountain to climb.

Though the normally- unflappable Dutchman felt aggrieved at the decision by referee Craig Thomson after he had brought down Peter Pawlett as the youngster surged into the box, his real beef should be with team-mate, Efe Ambrose.

On a real off night for the Nigerian, it was his mis-placed pass to Charlie Mulgrew just inside his own half which allowed Adam Rooney to drive at the heart of the Hoops defence - which comprised only Van Dijk at that point - and set up Pawlett to make the dart forward which forced the foul 19 yards out.

Though Barry Robson could not capitalise on the free kick, the damage was only delayed.

The reshuffle of the side saw Mulgrew drop back alongside the jittery Ambrose and Anthony Stokes moving into left midfield, leaving Leigh Griffiths to forage alone up front.

The bookings for the new Bhoy for a foul on Jonny Hayes and for Ambrose when he panicked as Pawlett spun away provided proof just how rattled Celtic were.

Lennon will have learned much about the character and temperament of his players during this fraught period.

While he did all he could to urge them to push up and not allow the Dons to pin them back, his instructions were, largely, ignored.

He could only look on in anguish as the hosts' attacks became more and more dangerous, until, four minutes from the opportunity to get his players in to regroup, Hayes took aim and blasted a 28-yard rocket high past Fraser Forster.

It was the first goal the keeper had lost in the league since Niall McGinn scored for the Dons in their 3-1 defeat at Parkhead on November 23.

Like Hayes' shot, Edwin van der Sar's British clean- sheet record was also beyond the reach of the Geordie.

And, like buses, having finally seen one goal come along, another was not far behind.

Right on the interval, a cross from the right by Niall McGinn was met by Rooney, who stole in ahead of his static markers to divert the ball in at the far post.

Skipper Scott Brown had a few choice words to say to Ambrose for his contribution to this second slip-up.

But, truth be told, the man who appeared to have rid himself of this capacity to implode needed no one to tell him what a starring role he was playing in this horror show.

The cold facts to be digested by everyone in the Celtic camp, not just Ambrose, is that Aberdeen have scored five goals against Celtic in their last three games.

The real question now is: Can the Dons convert this ability into a genuine challenge for the title? They are already in the League Cup final and favourites to lift the Scottish Cup after knocking out Celtic.

Derek McInnes' men have been the nearest (a relative term) challengers in the league this term, but even they are almost the length of the A90 behind.

Their manager is honest enough to admit that they can't realistically be expected to bridge such a yawning gap.

But, their performances - and results - against Celtic gives the lie to the belief that Lennon's side get it easy.

The thousands who made the long journey to Pittodrie did at least see their heroes roll up their sleeves and try their best to haul themselves back into last night's game with a spirited second half.

James Forrest, a half-time replacement for Kris Commons, gave them something to cheer about when he side-footed high into the postage stamp corner after good build up play by Brown.

With 29 minutes left, it meant a lifeline had been thrown, though that's no excuse for the green flare which was ignited in celebration.

When Georgios Samaras replaced the injured Griffiths on 77 minutes, the reaction was not so raucous.

And, while Amido Balde's arrival for Emilio Izaguirre did raise a cheer, there was to be no final twist in this tale of the not-so-unexpected.