Goals from Andy Halliday and Liam Boyce were enough for Hearts to secure their first league win in Paisley since 2010.
Joe Shaughnessy pulled one back for the home side, before Kristian Dennis was shown a straight red card for an elbow on Peter Haring.
The win means that the Jambos move to the top of the league for now at least with the remainder of their rivals in action tomorrow.
Hearts returned to the SMISA Stadium for the first time since that pitiful night in March of last year.
Jonathan Obika’s second half strike won the game for the Buddies that night and effectively relegated Hearts with the season called to halt shortly after due to the Covid-19 pandemic.
Only two who started that night lined up this afternoon with regular starters Craig Halkett and Michael Smith starting in defence. However, fellow defender Steven Kingsley missed out for the Jambos through illness and was replaced by Peter Haring.
Robbie Neilson’s side still lined up in their favoured 3-4-3 formation with Andy Halliday moving to left wing back.
There may have been no Hearts fans in the stadium, but Craig Gordon and Robbie Neilson were certainly loud enough to give the Jambos faithful a run for their money, when Mackay-Steven was on the end of a heavy aerial challenge from Greg Kiltie after just three minutes.
Liam Boyce went close with a glancing header from a Michael Smith cross, before Curtis Main fashioned a chance for himself, before dragging his left footed shot wide of Gordon’s near post.
The visitors had been the better side and they took a deserved lead after 18 minutes with a lovely move finished off by Andy Halliday.
Boyce received the ball on the left-hand side of the box and with the St Mirren defence expecting a shot, he instead chipped the ball inside for Halliday, who with his left foot looped the ball over Jak Alnwick and into the top corner.
Saints responded well and Jamie McGrath was unsurprisingly at the heart of everything the Buddies were creating from open play. Curtis Main was causing problems along with Eamonn Brophy, the latter largely trying to beat the Hearts offside trap by making late runs in behind.
Mackay-Steven blazed over just three minutes before half time and the final action of the half saw Richard Tait’s penalty appeals waved away by referee Gavin Duncan.
Jim Goodwin’s side failed to test Craig Gordon in the first half and that would’ve been at the top of the list regarding the Buddies boss’ half time team talk.
Brophy isn’t a shot shy striker and had two similar efforts saved by Gordon within five minutes of the restart as St Mirren pressed for an equaliser.
The home side were well on top in the opening 15 minutes of the second half and an ambitious volley from Main almost levelled the scores on the hour mark.
The St Mirren pressure forced Robbie Neilson into a change with Armand Gnanduillet replacing Josh Ginnelly who had a very quiet game by his usual standards.
Mackay-Steven again took a sore one after 65 minutes. Charles Dunne this time was the accused and Robbie Neilson received a yellow card from Gavin Duncan for his reaction to the challenge.
St Mirren had been the better side in the second half, but Hearts doubled their lead with just over 15 minutes to go. Substitute Gnanduillet used his strength to hold the ball up and the ball was worked left to Boyce, who checked back in-side on to his right foot and fired a low shot into the bottom corner past Alnwick.
Aaron McEneff replaced Mackay-Steven after 76 minutes minutes and within minutes of his introduction he glanced the outside of the post with a long-range thunderbolt.
St Mirren had struggled to create chances from open play so Robbie Neilson would have been desperately disappointed to leave Joe Shaughnessy unmarked in the box to head home and give Saints a lifeline with four minutes of normal time to go.
Straight from the restart there was more drama. Saints substitute Kristian Dennis appeared to flick an elbow out towards the head of Peter Haring. Referee Gavin Duncan seemed to have a clear view of the incident and showed no hesitation in brandishing the red card in the direction of the Saints forward.
Michael Smith should have made the points safe in stoppage time but was denied by the hand of Jak Alnwick. Nevertheless, Hearts saw out the five additional minutes and move to the top of the table with six points out of a possible six.