Harry Cochrane scored on his return from injury as Hearts made it two wins from two in the SPFL Reserve Cup.
The 17-year-old midfielder was making his first appearance since picking up a knee injury last month and found the net on 42 minutes, steering home a loose ball.
The Jambos went on to win the match 3-2 and now sit top of Group C in the competition.
Kilmarnock took the lead on 38 minutes thanks to a strike from Oliver McDonald, but Cochrane’s goal put the teams level at the break.
The visitors were reduced to ten men on 63 minutes when Ross Millen was shown a straight red card, but it did not deter them as four minutes later Iain Wilson netted to put them ahead.
However, Hearts battled back and substitute Dario Zanatta levelled as Killie failed to clear a corner before the Canadian turned provider for Cammy Logan to fire home via the crossbar on 83 minutes.
Hearts: Silva, Gadja (Henderson 78), Logan, Baur, Petkov, Ritchie, Moore, Cochrane, Keena (C Smith 84), Wighton, Amankwaa (Zanatta 63). Unused subs: Mason, Leddie, Makarova.