Hearts moved up to third in the cinch Premiership with a spirited 1-0 victory over Kilmarnock at Rugby Park.
A goalkeeping error from Will Dennis was enough to ensure that Derek McInnes marked his 700th game in management with a defeat.
Dennis turned Lawrence Shankland’s shot into his own net after 18 minutes and, despite controlling possession for much of the game, the hosts were unable to come up with a response.
Hearts have leapfrogged St Mirren to move into the top three, while Killie have dropped to seventh having suffered their first league defeat at Rugby Park in six matches.
McInnes made two changes to the side that was held to a goalless draw against Ross County in their previous outing. Corrie Ndaba and Kyle Vassell were preferred to Rory McKenzie and Matthew Kennedy – who both began the game on the bench.
There were also two changes for Hearts, with Calem Nieuwenhof and Yutaro Oda handed starting berths.
The first chance of the match went the way of the hosts, Liam Donnelly blazing wide after David Watson had done well to keep the ball in play.
It was the hosts who had made the much brighter start and Ndaba had a shot that flew past the post before he then headed over after rising highest to meet Marley Watkins’ cross.
Hearts had struggled to create anything of note in an attacking sense, though it would take a good block from Lewis Mayo to divert Liam Boyce’s powerful effort behind for a corner.
A quick VAR check deemed there was no handball inside the area from the resulting corner before the visitors broke the deadlock two minutes later.
Shankland burst forward and angled a shot towards the Killie goal that slipped through the grasp of Dennis and into the net.
The home side passed up a glorious chance to level after Danny Armstrong picked out Watson but he was unable to work Zander Clark.
Much of the attacking threat from Hearts was coming on the break and Boyce was unable to take advantage after being released following some neat play from Nieuwenhof.
Boyce limped off on the half-hour mark to be replaced by Toby Sibbick, a setback to the striker who spent the majority of last season sidelined with a torn cruciate ligament.
There was a moment of controversy with five minutes remaining in the first half when Dennis rushed from his goal before clattering into Oda. The offside flag had been raised, though the keeper still was shown a yellow card and was spared a red after referee David Dickinson consulted VAR.
A fizzing cross by Armstrong evaded all inside the six-yard box and the winger would continue to torment the Hearts back-line when he found Ndaba, who saw his point-blank header kept out brilliantly by Clark on the stroke of half-time.
Watkins had a penalty claimed turned down after yet another VAR check just after the restart and for all the home side’s possession they were struggling to trouble the Hearts keeper.
Good work from Shankland led to Sibbick having a low drive blocked, while at the other end Donnelly’s strike cannoned back off the legs of a Hearts defender and away to safety.
Armstrong’s back-post header was easily smothered while Alex Cochrane and Alex Lowry both went close at the other end.
McInnes’ side would spurn two good chances in injury time, Stuart Findlay headed over Kennedy’s corner and then Donnelly blasted straight at Clark from inside the six-yard box.