Scott Brown’s deflected strike in an extraordinary finale to an absorbing contest moved Brendan Rodgers’ side eight points clear of Rangers at the top of the Premiership with just 12 games remaining.
Brown’s goal sparked briefly chaotic scenes as some visiting fans spilled onto the pitch at both ends of the ground, while the Celtic captain’s celebrations saw him sent off as he picked up his second booking of the afternoon.
The result was harsh on Kilmarnock whose hopes of a third consecutive home win over Celtic were handicapped by Kirk Broadfoot’s straight red card with 15 minutes remaining.
Even on an artificial playing surface they make no secret of loathing, Celtic were entitled to have a spring in their step at Rugby Park. Rangers’ slip-up at home to St Johnstone the previous day had provided them with the opportunity to exert even firmer control of the title race which they ultimately seized.
Odsonne Edouard, making his first start since mid-December as he replaced Oliver Burke up front, was one of three changes Rodgers made to his starting line-up after the sobering Europa League defeat at home to Valencia. Jonny Hayes and Kristoffer Ajer came in to a reshuffled defence at the expense of Emilio Izaguirre and Jozo Simunovic.
Edouard made a lively start and was first to threaten for the champions in the eighth minute. After good link-up play down the right from Jeremy Toljan and James Forrest, the French striker received the ball in the penalty area and saw his left foot shot on the turn drift narrowly wide of Daniel Bachmann’s left hand post.
Celtic were bright and progressive in the opening stages and carved out another opening for Edouard three minutes later. It was Callum McGregor and Ryan Christie who combined this time to find Edouard and his firm drive was well saved by Bachmann.
It took Kilmarnock time to build up any rhythm but the customary intensity of their pressing game eventually saw them start forcing Celtic onto the back foot for spells. The home side’s first sight of goal fell to Broadfoot and the big defender might have done better than glance his header wide after being picked out by Chris Burke’s perfectly delivered corner.
Killie continued to grow in confidence, sparked by the ball-winning attributes of Alan Power. The Irish midfielder, free to play after escaping retrospective punishment for his high boot foul on Rangers’ Ryan Jack the previous weekend, isn’t likely to ever change the way he plays. A similarly high challenge on Brown early in the game here was proof of that.
Power is as effective as he is robust, however, and his tenacity set up the next chance for Kilmarnock when he sent Eamonn Brophy racing into the penalty area. The striker worked space for a shot but failed to trouble Scott Bain as the ball trundled wide of the Celtic goalkeeper’s right hand post.
Brophy, back in the Killie side after injury, was causing the visitors’ defence problems with his pace and movement. He looked poised to put Killie ahead in the 31st minute when he was played in by Burke but his shot was kept out by Dedryck Boyata’s superbly timed block.
As Celtic struggled to rediscover their earlier fluency, Brown picked up the first booking of the afternoon for a poorly timed challenge on Greg Taylor.
Kilmarnock carried the momentum they had built into the second half as Celtic continued to look uneasy in defence. Ajer’s clumsy challenge on Conor McAleny gave the hosts a free-kick in a dangerous position but Burke’s effort sailed comfortably over Bain’s crossbar.
Clarke’s men had the ball in the net in the 61st minute but the fine finish from McAleny was disallowed as the on-loan Fleetwood Town striker used a hand to control Jordan Jones’ cross before rifling a shot beyond Bain.
Edouard had become an increasingly peripheral figure for Celtic since his promising start to the contest and he was withdrawn with just over 20 minutes remaining, Rodgers introducing Burke in a bid to inject fresh zest to his attack.
Christie fizzed a free-kick narrowly over as Celtic tried to increase the tempo in the closing stages and the balance looked to have tipped in their favour when Broadfoot was dismissed for a studs-high foul on Brown right in front of referee Bobby Madden. The former Rangers defender could have little complaint at the decision.
There remained little hint at the even later drama to come, however. Hayes swung over a couple of decent crosses, which Christie and then Boyata were unable to convert with close range headers, and Kilmarnock looked on course for a point which was the least they deserved for their efforts.
But the 90th minute brought delirium for the visiting support and heartbreak for Killie. Substitute Vakoun Bayo, making his debut for Celtic, won a corner which McGregor floated in from the right. Boyata nodded the ball back across the penalty area and Brown let fly with a volley which took a deflection off the arm of Killie sub Alex Bruce before beating the helpless Bachmann.
The significance of the goal saw both Brown and some Celtic fans unable to contain their emotions. The skipper collected his second yellow card while some visiting supporters spilled onto the pitch.
Celtic substitute Timothy Weah struck Bachmann’s left hand post during four frenetic minutes of stoppage time, then was booked as feelings continued to run high among both sides at the final whistle.