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.
9. Barrie McKay - 8
The team’s most dangerous players. Such a creative presence. Sometimes plays passes which don’t seem on and even his team-mates don’t seem on his wavelength. Crated the best opportunities, setting up Gary Mackay-Steven and Michael Smith before assisting GMS for the opener. Photo: Craig Foy - SNS Group
10. Liam Boyce - 7
A positive return to the starting line-up, providing that focal point and link in attack. A great influence in the build-up. Has a good relationship with Barrie McKay. Left fans frustrated in the first half when he took too long to get a shot away and ended up tickling one at Jak Alnwick. Photo: Mark Scates - SNS Group
11. Gary Mackay-Steven - 6
An interesting afternoon. Was on the verge of being replaced before opening the scoring with a nice side-footed finish. Up until then he had been largely frustrating, lacking the confidence to take an opponent on or be ruthless. Photo: Ross MacDonald - SNS Group
12. Josh Ginnelly - 6
Busy and energetic off the bench. Always a threat on the break. Photo: Ross MacDonald - SNS Group