Kilmarnock came from behind to beat Celtic 2-1 at Rugby Park in the Ladbrokes Premiership on Sunday afternoon.
Leigh Griffiths gave the visitors a half-time lead but Chris Burke equalised and Stuart Findlay headed the winner for Steve Clarke's men in stoppage time.
Hearts have a five-point lead at the top of the table but Rangers are up to second spot after thumping St Johnstone 5-1 at Ibrox.
James Tavernier, Alfredo Morelos, Scott Arfield, Kyle Lafferty and Daniel Candeias were all on target for Steven Gerrard's team, with Blair Alston (penalty) replying for Saints.