Aberdeen battled back from two goals down to salvage a 2-2 draw at home to Inverness but missed the chance to go top of the Ladbrokes Premiership.
The Dons came into the match seeking a fifth successive victory but goals either side of half-time from Liam Polworth and Greg Tansey looked to have put Inverness on course for a second upset win over Derek McInnes' men this season.
However, Niall McGinn got Aberdeen back in the game with 17 minutes left and then Adam Rooney slotted home a stoppage-time penalty to snatch a point for his side, which means they trail Celtic only on goal difference.
Inverness had already brought to an end one impressive Aberdeen run this term, triumphing 2-1 at home in September to halt the Dons' eight-game winning streak at the start of the campaign, and they gave early warning of their intent to do likewise on Saturday with a Miles Storey shot that goalkeeper Danny Ward blocked.
That came after just 10 minutes, and not long after Aberdeen were caught again with Storey once more the man set free.
This time his deflected shot had to be pushed around the post by on-loan Liverpool goalkeeper Ward.
Aberdeen's only decent effort on goal until that point had been a Kenny McLean free-kick from distance which squirted wide of the upright.
And Inverness were rewarded for their first-half efforts when they took the lead four minutes before the interval, Ross Draper doing well to hold off the challenge of Paul Quinn before cutting back for Polworth to stroke home from eight yards.
And just two minutes after the interval, Tansey doubled the advantage from the penalty spot. Quinn seemed to slip as Draper went past him and in the process bundled the Inverness man over.
Referee Willie Collum had no hesitation in pointing to the spot, and Tansey stepped up to send Ward the wrong way.
Goals from this afternoon's Willie Collum show. pic.twitter.com/768XPMZYzB— ByTheMin Aberdeen (@ByTheMinAFC) December 26, 2015
It was looking grim for Aberdeen but their response was strong, and McGinn cut the deficit after 73 minutes.
McGinn caught Gary Warren in possession before advancing on goal and beating Inverness goalkeeper Owain Fon Williams from close range.
The Welsh goalkeeper had earlier received lengthy treatment for a head injury, but had continued, and he somehow got a fingertip to turn McLean's 86th-minute piledriver onto the crossbar.
But Aberdeen were not to be denied, and Collum gave a second spot-kick of the game in the 90th minute.
Substitute David Goodwillie's shot into a ruck of bodies was adjudged to have come off an arm, and Collum again saw enough to point to the spot.
The cool figure of Rooney stepped up, and he drove the ball to the goalkeeper's right as he dived in the opposite direction, to earn McInnes' side a share of the spoils.