The Jam Tarts ran out 2-0 winners with goals from Gary Mackay-Steven and a superb Steven Kingsley free-kick.
It was a slog at times, especially in the first-half where St Mirren were the better side. Hearts had Craig Gordon to thanks for keeping them in it with at least five saves before the opening goal arrived.
Once Hearts got in front they grew in confidence and fully deserved their three points with Joe Shaughnessy being sent off late on for the visitors.
So how did the players rate out of ten?
Player ratings scale - 10: One of the best performances you've seen. 9: Outstanding. 8: Very good. 7: Good. 6: Average. 5: Poor, 4: Very poor. 3: A terrible day at the office. 2: Abysmal. 1: One of the worst performances you've seen.
Once Hearts got in front they grew in confidence and fully deserved their three points with Joe Shaughnessy being sent off late on for the visitors.
5. Michael Smith - 6
A standard Michael Smith performance. Didn’t put a foot wrong defensively, while supporting the attack. Passed up two chances, one of which he should have scored.
Photo: Ross MacDonald - SNS Group
6. Beni Baningime - 6
An understated performance in midfield. Hearts struggled to control the game in the first half but Baningime always looked to get on the ball. Not one who will do much with it in the final third but trusted not to give it away.
Photo: Ross Parker - SNS Group
7. Cammy Devlin - 7
Snapped into challenges, harried and picked up on loose balls. Excellent without the ball and such a pest. He must be a nightmare to play against. Influence grew with the ball after some sloppy play in the first half.
Photo: Craig Foy - SNS Group
8. Andy Halliday - 6
A few eyebrows were raised when he was included in the starting line-up. He didn’t let Robbie Neilson down. Battled up against Richard Tait and waas a solid, defensive presence on the left.
Photo: Ross MacDonald - SNS Group