A stoppage-time header from Steffen Wohlfarth saw Ross County hit back from two goals down to stun Celtic.
County keeper Michael Fraser saw a Charlie Mulgrew corner sail straight in and could only claw a curling chip from Gary Hooper into his own net.
But Grant Munro thundered in a shot from 18 yards while Sam Morrow scrambled in from close range to level.
And an entertaining second half ended on a note of high drama as Wohlfarth nodded in to seal a memorable victory.
It was the German striker's first goal since his January move to the Highlands and extends the Staggies' unbeaten run to 11 games.
County have not lost since a 4-0 defeat at Celtic Park on 22 December, collecting 27 points along the way - two more than Celtic have gathered in 12 games.
The visitors, who saw their Champions League adventure come to a end in Turin on Wednesday, have now lost two consecutive Scottish Premier League matches but retain a healthy 15-point lead at the top.
County's win was all the more impressive considering they were without the in-form Ivan Sproule and suspended captain Richard Brittain, while Fraser continued to deputise for the injured Mark Brown.
Conditions were difficult on a sandy, bumpy pitch with an icy, strong wind above but the visitors adapted well initially, with Hooper's angled shot turned away by Fraser.
The resulting corner was cleared but Mulgrew got another chance to deliver and made the most of it as he swerved the ball straight in.
Fraser then saved well from Miku after the Venezuelan had played a one-two with Hooper but he was beaten again soon after.
Dylan McGeouch laid the ball back for Hooper and the English striker clipped a first-time curler towards the far post from 18 yards with Fraser only able to help it into the net as he was caught off his line.
County responded in style when Munro seized upon a poor defensive header from Kelvin Wilson to thump an unstoppable shot into the top corner of Fraser Forster's net.
And the home side were level on 36 minutes when Iain Vigurs nutmegged Mulgrew on the right wing and skipped round Joe Ledley before hanging a cross to the far post.
Morrow and McGeouch challenged for the ball and the County forward reacted quickest to force the ball home.
Anthony Stokes should have put Celtic back in front with the last kick of the half but he drilled wide from 15 yards after Miku had found him unmarked.
The hosts had a let-off after the interval when Fraser palmed out Hooper's fierce shot and it bounced off the head of defender Mihael Kovacevic before clipping the top of the crossbar.
Celtic's Efe Ambrose was next to breath a sigh of relief when his poor back-header fell to Martin Scott but the County midfielder's shot on the stretch was scuffed straight into the arms of Forster.
Kovacevic, Stuart Kettlewell and Munro all fired ambitious efforts wide as Celtic grew jittery and County gained the ascendancy.
Wohlfarth had a great chance with 10 minutes left when he raced onto a pass from Paul Lawson but he scooped a first-time effort wide of the target with Fraser beaten.
As the final seconds ticked by, the replacement striker was given another opportunity and he snatched a famous win when he was first to a long ball by Evangelos Ikonomou and nodded over the onrushing Forster.