The Kilmarnock manager threw on Steven Naismith in the quest for an equaliser in this pulsating fourth-round tie and the teenaged substitute dramatically forced a replay with a last-minute goal.
It was the second time in four days that Hearts's ambitions had suffered such a cruel blow, Motherwell robbing them of a place in the Scottish League Cup semi-final with the last kick of the game.
The Edinburgh side must have thought their luck had changed when they surged ahead after just 16 minutes through Dennis Wyness. It was the striker's seventh goal since new manager John Robertson had restored him to the side after Craig Levein's departure in November.
Wyness showed clever movement to elude his marker and meet Robbie Neilson's cross from the corner flag, angling a firm header beyond keeper Alan Combe.
It took Combe and the woodwork to deny Wyness a second goal six minutes later. Saulius Mikoliunas created the opening and Wyness exploited it with a deft curling shot from the edge of the box. It struck the inside of the post and came back out, only for Combe to deny Lee Miller with a Rene Higuita-style scorpion kick.
The reward for Combe's eccentricity was to see his side restore parity after 25 minutes. Allan Johnston skipped past teenage full-back Lee Wallace and delivered a dipping cross that was met by Colin Nish who buried his header past Craig Gordon.
Kilmarnock might have gone in ahead at the interval had it not been for the vigilance of Andy Webster. The Scotland defender cleared Kris Boyd's shot off the line and Miller profited from that escape in stoppage time.
The striker supported Paul Hartley's searing burst from the Hearts half, and was picked out by the midfielder. He kept his composure to thrash a shot past Combe.
Hartley had the best opportunity of all to kill the visitors off in the second half, racing onto Mikoliunaus's sublime pass and advancing on Combe only for the keeper to paw away his shot.
That miss came back to haunt Hearts when Naismith struck in the last minute. Combe's free kick was flicked on by Boyd for the teenager to rifle into the roof of the net.Reuse content