A first-half brace from Billy McKay was enough to seal the victory for Terry Butcher's men, who remain unbeaten at the top of the table.
McKay should have sealed his hat-trick but missed from the spot following Jamie Hamill's red card for deliberate handball.
Inverness remain three points ahead of Celtic, who kept the pressure on at the top with a dramatic 1-0 win at Dundee United in the day’s early kick-off.
Neil Lennon's side enjoyed a comfortable 3-0 win over Shakhter Karagandy in midweek, a victory that sealed their place in the group stages of the UEFA Champions League.
The hosts took the lead five minutes after half time when Kenny McLean tucked away David van Zanten’s cross, before Kallum Higginbotham levelled with a superb curled effort half an hour later.
Ross Forbes made the points a certainty just three minute later when he came off the bench to lash home and heap more misery on Danny Lennon’s side.
Goals from Henri Anier and John Sutton cancelled out Darren Barr’s 17th-minute header.
