St Mirren's six-match unbeaten run came to an end at Tynecastle as the Buddies were narrowly beaten by Hearts.
Stephen Robinson will be scratching his head as to how his side didn't take at least a point after a strong performance in the capital.
The manager had to contend with suspensions to Marcus Fraser, Charles Dunne and Ethan Erhahon while Ryan Strain couldn't recover in time after his injury against Hearts on Saturday. There was a first start for January signing Richard Taylor with Declan Gallagher returning from a back spasm that ruled him out of last weekend's draw. Ryan Flynn also came into the side.
Saints had the first real chance of the game on 12 minutes when Curtis Main shot into the arms of Zander Clark. A Saints corner was only cleared to the edge of the box where Mark O'Hara headed back in. Two Hearts players collided as they looked to clear and it fell to an unmarked Main who turned and curled towards the far corner with Clark managing to gather. A minute later Keanu Baccus fired wide 20 yards from goal after spinning away from the Hearts defence.
Hearts had their first opportunity on 16 minutes with their captain Lawrence Shankland seeing a header saved by Trevor Carson. Shankland was fouled on the edge of the area by Declan Gallagher and it was the Hearts skipper who got his head on the end of Robert Snodgrass' ball in, but Carson was equal to the effort.
Baccus was first to go into the book when referee David Munro said the Australian had caught Snodgrass on the halfway line. It was a harsh booking for the Saints midfield man as it looked like he didn't touch the former Scotland international.
The home side took the lead just before the half-hour mark with Barrie McKay opening the scoring for Robbie Neilson's men. The Jambos winger started the move with a nice one-two before Andy Halliday received the pass from McKay and laid it back to the winger who fired into the corner of the net.
Saints were immediately dealt another blow as O'Hara picked up an injury and had to be replaced by Greg Kiltie. The substitute had a chance to restore parity on 36 minutes when he received the ball 20 yards from goal, but under pressure from the Hearts defence he fired wide.
Taylor - on his first start for the Buddies - made a terrific challenge to deny Hearts a second a few minutes before the interval when Shankland had looked to get his shot away after finding space in the box.
Hearts started the second-half well as they looked for a quick second to put the game beyond Saints. Andy Halliday will have felt he should have done better on 56 minutes when scooped over from 15 yards. Two minutes later, Taylor made another brilliant block from Josh Ginnelly.
Snodgrass then went into the book for Hearts after catching Baccus late in the middle of the park. VAR checked for a potential red card but it remained a yellow.
Saints were having a decent spell after the hour mark with Kiltie lashing inches over the bar on 65 minutes. Flynn's low cross was cleared only as far as Kiltie and the midfielder steadied himself before firing over from the edge of the area.
Stephen Robinson made two changes on 67 minutes when he replaced Baccus and Alex Greive with Dylan Reid and Jonah Ayunga. The latter almost got the Buddies level just four minutes after coming on. The forward went on a brilliant driving run and had a go from 20 yards with Clark touching onto the post and behind for a corner. Main headed just over from the resulting corner.
Jonah Ayunga almost made an instant impact after coming on as a sub with his effort coming off the post (Image: Craig Brown)
Saints should have drawn level with eight minutes of normal time remaining but for two great saves from Clark in the Hearts goal. The ex-St Johnstone man first denied Kiltie before he was quickly up to push away Main's strike. Hearts couldn't clear the danger with Ayunga then blasting into the side net.
The Buddies had a strong appeal for a penalty turned down when Kye Rowles looked to have handled Scott Tanser's cross. VAR had a look but controversially said no penalty.
Hearts almost grabbed a second on the counter as we headed into added time. Substitute Garang Kuol sent Stephen Humphrys one-on-one with Carson but the Jambos man somehow knocked wide.
Saints kept pushing for an equaliser and were inches away from earning a point in the final seconds when Main dragged agonisingly wide on 95 minutes.
Full-Time: Hearts 1-0 St Mirren
St Mirren: Carson, Gallagher, Shaughnessy (c), R.Taylor (Brophy 85), Flynn, Baccus (Reid 67), O'Hara (Kiltie 33), Gogic, Tanser, Greive (Ayunga 67), Main
Subs Not Used: Urminsky, Campbell, Kenny, F.Taylor, Olusanya
Hearts: Clark, Hill, Sibbick, Rowles, Smith, Halliday (Forrest 87), Snodgrass, Cochrane (Devlin 60), McKay (Kuol 77), Ginnelly (Humphrys 77), Shankland (c)
Subs Not Used: Stewart, Grant, Kio, Atkinson, Oda
Referee: David Munro
Assistant Referee: Drew Kirkland
Assistant Referee: Andy Milne
Fourth Official: Graham Beaton
Jonah Ayunga wheels away in celebration after netting the second goal in our 2-0 win against Celtic in September (Image: Allan Picken) 
