Hearts visit Celtic on Sunday for a top-of-the-table clash with their eight-point Scottish Premiership lead gone, after Bruce Anderson's 90th-minute leveller for struggling Kilmarnock left them without a win in four games.
Having won one of their previous five matches, Derek McInnes' Hearts were in need of a victory against the manager's former club to refuel chat of a serious Tynecastle title challenge.
Lawrence Shankland's 11th goal of the season, a lofted finish following a Tomas Magnusson pass, looked set to provide that.
But Anderson's late equaliser, a rebound after goalkeeper Alexander Schwolow fumbled Liam Polworth's strike from distance, extended Hearts' stuttering form.
McInnes' men still lead the table on goal difference, but Celtic are now level on points and have a game in hand with Sunday's match at Parkhead looming.
Kilmarnock's winless run stretches to eight games, but this point will serve as a huge boost for Stuart Kettlewell and his players.