Rangers' title hopes were left hanging by a thread after a 2-1 defeat to Kilmarnock.
Ayrshire was famously the venue where the wheels came off for Steven Gerrard's team during last season's championship race and Gers were left with another dose of Rugby Park regret on a hugely damaging evening.
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Goals from Stephen O'Donnell and Eamonn Brophy saw Rangers slip 10 points behind leaders Celtic - who stormed to a 5-0 win at Hearts.
The Ibrox side still have a game in hand and two Old Firm clashes to play but Neil Lennon's Hoops will believe they have one hand on a ninth successive title.
Scott Arfield had fired Gers ahead but the hosts played on the visitors' nerves to claim a victory which keeps them just a point outside the top six.
How Kilmarnock stunned Rangers...
Kilmarnock chiefs stuck with the decision made last season to limit the travelling faithful to one stand rather than the two they traditionally received. The result was a subdued atmosphere, mirrored on the pitch by a drab opening quarter hour.
Gary Dicker raised the hackles of the away support as he picked up a booking after snapping at Ianis Hagi's ankles but that did not deter the Romanian, who created Gers' first real opening on 23 minutes as he played a first-time ball off Andy Halliday's pass to put in Joe Aribo. But Dario Del Fabro recovered quickly to force the Nigeria playmaker into firing wide.
Killie had their big chance four minutes later as former Ibrox winger Chris Burke took his old side by surprise by pulling a corner back to the edge of the box for Alan Power but the Irishman's strike soared over.
The volume was finally turned up on 32 minutes, however, as Arfield repeated his weekend rocket against Hamilton to open the scoring.
A clever flick from Aribo set Gers racing forward. Stuart Findlay got across to deny Alfredo Morelos a strike but Killie switched off from the corner, allowing Halliday to spray the ball to Arfield in acres of space 25 yards out.
The Canada international's strike had a bit of movement but Jan Koprivec - deputising for suspended Killie number one Laurentiu Branescu - should have done more than watch it sail into the corner.
Arfield almost walked off at the break with a second as he caught a Niko Hamalainen clearance with a clean left-foot volley which whistled just wide of Koprivec's right-hand post.
Killie's response was stepped up after the interval. Brophy's deflected strike went close before his side bombarded the Gers box with corner after corner.
Then came a demonstration of the two sides of Morelos. First he ended up with his name in referee John Beaton's book as he was booked by the referee when he threw himself over at Hamalainen's feet inside the box.
Moments later he almost doubled Rangers' lead with an audacious lob over the on-rushing Koprivec from out wide which landed on top of the crossbar.
But with Rangers failing to build on their lead they remained vulnerable and so it proved as Killie levelled. Halliday got sucked out wide on the right as he chased Burke and could not get back into position in time as the ball was fired back in from the left by Hamalainen, with O'Donnell left free to sweep home.
Morelos' frustration levels took him close to the edge again. He got away with another ridiculous dive but shot a look of disbelief as Beaton as he had a headed goal harshly chopped off for a push on Del Fabro.
It was Gerrard who was left stunned two minutes from time as his team failed to deal with a long straight ball to Brophy, who angled a low finish away from Allan McGregor to all but kill off Rangers' title dreams.
What the managers said...
Kilmarnock boss Alex Dyer: "I'm delighted. It was a great night for the football club. It was a terrific finish from Eamonn at the end and a great result for us. I thought we would get chances as the game wore on.
"We contained them to a to a degree but showed them too much respect in the first half. After the break was much more like us and we were confident of causing them problems. I sensed a vulnerability in them a little bit as we asked questions of them."
Rangers boss Steven Gerrard: "In the second half, we never handled the heat or the pressure. We never played like a team that was trying to fight to remain in a title race, a team that was trying to come away from here with three points.
"The reality is the opposition [Celtic] are in the driving seat. That's down to two things - their form and us not being good enough since the winter break. But I'm responsible for that. I put this group together. I coach them, they are my tactics and decisions. So, I'm not going to sit here and try and force any blame in any other direction than myself.
"It's disappointing, it's frustrating at the moment. We keep going, we keep fighting and see where we are. But on the evidence of the second half tonight, it's very worrying for me right now."
Rangers take on Livingston at Ibrox on Saturday at 3pm while Kilmarnock host Hibernian on Sunday at 4.30pm.