The first two chances fell to Kilmarnock, with Michael Fraser called into action in the first minute to tip a drive from James Fowler over his bar.
Danny Invincibile’s shot was then pushed wide by the Inverness keeper.
Imrie opened the scoring on 10 minutes courtesy of a sublime left-footed free-kick from the edge of the area.
Marius Niculae then shot wide and headed over for the home side.
The hosts doubled their advantage in the second half when Imrie whipped in a cross and David Lilley haplessly drove the ball past his own keeper.
Kilmarnock’s afternoon then got worse.
Ross Tokely’s pass was well controlled by Niculae, who hit a superb shot high into the roof of Combe’s goal on 79 minutes.