James Dayton netted with a superb strike as Kilmarnock beat St Mirren at Rugby Park.
Cillian Sheridan headed his first Killie goal to put the hosts ahead against the run of play.
St Mirren's Lewis Guy had earlier been denied twice in quick succession by keeper Kyle Letheren.
The hosts took control after the break with James Fowler firing a second and Dayton hammering into the top corner before Paul McGowan's late consolation.
The Rugby Park side now join the Buddies on nine points after seven matches.
Dayton's goal put Killie three up before St Mirren's late consolation
Kenny McLean lifted a shot over the Kilmarnock crossbar early on before Michael Nelson came even closer for the hosts with a stinging low drive that skimmed the outside of the post as St Mirren struggled to deal with a corner.
A dithering Manuel Pascali gifted possession to McGowan, who sent Guy clean through on Letheren's goal but the stopper made an excellent save.
And Letheren was Kilmarnock's saviour again moments later after more carelessness in possession allowed Guy in to try and round the keeper, the Welsh keeper got a strong hand on the ball before Steven Thompson blazed the resulting loose ball high wide.
Killie were struggling to get a foothold in the game and there was more frustration for the home fans when a promising break involving Sheridan was halted by a handball by Marc McAusland, who was booked.
But Killie then capitalised on slackness by St Mirren as Jim Goodwin conceded possession and the ball was worked out to Danny Racchi, whose superb cross from the right was crisply nodded into the net by Sheridan.
St Mirren tried to re-assert themselves and Paul Dummett was denied by Fowler's clearance near the goal-line after Letheren had failed to gather a high ball.
Kenny Shiels' side remained a threat on the break and Dayton escaped Goodwin before crossing for Harkins to head wide.
And they extended their lead as another Racchi cross bounced back off Sheridan to Fowler, who buried the ball past Craig Samson.
Dayton had looked dangerous on Killie's left and he got his reward for an enterprising display when he cut inside his man and unleashed a powerful angled shot beyond the reach of Samson.
That forced St Mirren manager Danny Lennon into action, he made a triple substitution with Thompson, McLean and David van Zanten making way for Sam Parkin, Dougie Imrie and David Barron.
And the changes did give the visitors fresh attacking impetus as Guy struck the bar from McGowan's delightful chipped pass but Parkin could not convert the rebound.
Dayton and Harkins were given a standing ovation from the home fans as they came off to be replaced by Rory McKenzie and Chris Johnston.
McGowan eventually found the net for the visitors, the former Celtic player driving low past Letheren from Parkin's headed knock-down seven minutes from the end.
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