The hosts took the lead in the 26th minute when a Jesus Garcia Tena slip-up let in Ryan Wallace and his cut-back was guided into the net by Andy Barrowman.
And the advantage was doubled four minutes later, Barrowman's cross from the right finding defender Jordan McMillan, who had ghosted into the box and provided a nice finish at the back post.
The hosts deserved their two-goal lead after dominating the half and they clinched the three points with another quick-fire two goal salvo in the second-half.
Just after the hour, Callum Morris sent the ball into the danger area and, after Barrowman had challenged, the ball fell nicely for sub Ryan Thomson, who steered it past Andy McNeil.
And Barrowman then grabbed his second of the afternoon four minutes later, running onto a Stephen Husband long ball and finishing with a delightful lob.