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.
But they left it late at Tannadice, in a game where chances were few and far between, before Anthony Stokes stepped up to curl home a sweetly struck free-kick three minutes from time, rounding off a terrific week for the champions.
Partick Thistle also managed to secure a late win over St Mirren at Love Street, leaving the home side still to record a win this season.
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.
The evening kick off saw Motherwell come from behind to see off Kilmarnock with a 2-1 win at Fir Park .
Goals from Henri Anier and John Sutton cancelled out Darren Barr’s 17th-minute header.
Motherwell were reduced to 10 men late on, but hung on to a win that moves them up to third in the table
Aberdeen were held to a goalless draw at home to St Johnstone, while there were also no goals in the clash between Hibernian and Ross County.
