ABERDEEN went into this encounter hoping for the win that would take them to the summit of the Clydesdale Bank Premier League.
Instead, it was Inverness Caledonian Thistle who find themselves, remarkably, equal with Celtic at the top of the division.
Two close-range efforts from Billy McKay and a Gary Warren header ensured the Highlanders took the points as their hosts capitulated in a thrilling contest. For visiting manager Terry Butcher, there was euphoria not only at the result but also at how his team performed in extending their run to just one loss in 13.
"Who knows what these boys can do this season," he said. "We wanted to make it special. Every week we're making history; we did at Celtic Park at the weekend by winning there for the first time and had our first clean sheet there, and now we're joint top, the highest we've been in our history. There's a lot more to come from these boys. They were tired and they never really got going until the second half."
Aberdeen, hampered by injuries to 10 players, fielded an unusual formation with Scott Vernon, a misfiring striker with only one league goal this season, given the role of marking Richie Foran, around whom much of the Inverness play centres. Joe Shaughnessy, a centre-back, was given his first competitive start on the left of midfield.
As the rain drizzled on to a Pittodrie pitch, scarred in places after hosting the rugby match between Scotland and Tonga on Saturday, this was a game that struggled to please in a dreary first half, despite Josh Magennis's bursting run into the penalty box, his final shot being saved between the legs of Antonio Reguero, the Inverness goalkeeper.
Half an hour later, however, Inverness struck on the break. Aaron Doran fed a long pass across goal, where McKay, the striker who put Celtic to the sword on Saturday, was poised to tap in his eighth goal of the season.
It was a piece of action that brought the game, and the hosts, to life and when they pressed for an equaliser it was the tenacity of Jonny Hayes, facing his former team-mates, that did most of the damage. The Irish winger evaded a clutch of defenders and cut the ball back for Magennis to fire home from close range seconds before the interval.
If both sides were keen to resume as soon as possible after the break, their patience was tested when Alan Muir, the referee, withdrew after suffering a calf injury and was replaced by fourth official Craig Charleston as a series of announcements went out over the public address system that another official was required.
The urgency of Aberdeen early in the second half was palpable and it took them just four minutes to establish a lead as Magennis, moved into a striking role, completed his first double for the club. The Northern Irishman accepted Niall McGinn's pass, turned Gary Warren in expert fashion, then sent his shot past Reguero.
It was a goal that was to spur on Inverness more than Aberdeen. The visitors' ability to mount quick counters presented Craig Brown's side with problems and when Hayes needlessly gave away a corner kick on the left, the set piece ended with Warren's clean header hitting the back of the home net.
Andrew Shinnie and Doran proceeded to tantalise the Aberdeen defence and might have found the goal a couple of times before McKay, with his ninth goal of the season, sealed their win eight minutes from the end of a pulsating contest with an opportunist effort from close-in.
Unsurprisingly, given what had been at stake, Brown was disconsolate. "To concede three goals as we did was most unsatisfactory," he said. "The game was there to be won and having gone behind early, we managed to take the lead and when you're in the lead at home you should never concede the way we did.
"Magennis scored two good goals, but his mistake in the first half resulted in Inverness getting one. So, it wasn't all good news for him."
analysis Aberdeen spurn chance to go top as remarkable Inverness steal their thunder