Inverness took the bragging rights from the first-ever top-flight Highland derby as Ross County slumped to a third successive defeat.
The hosts took the lead when Ross Draper connected with Graeme Shinnie's corner after strong early pressure.
And Terry Butcher's side doubled their lead when Andrew Shinnie finished after being set up by Richie Foran.
Iain Vigurs' free-kick gave County the chance of a comeback, but Aaron Doran's late strike secured the points.
The Caley Jags almost took the lead after only 25 seconds when Doran curled in a cross from the right which, inexplicably, Ross Tokely headed towards his own goal.
Luckily for the former Inverness defender the ball cannoned back off the bar to spare his blushes.
Less than a minute later Inverness could have been ahead again as Owain Tudor-Jones picked up on a one-two at the edge of the box.
However, his deft right-footed flick was cleared from under the crossbar by Grant Munro as County looked nervous at the back.
The home side took a deserved lead when Draper forced Graeme Shinnie's corner over the line with what looked like his shoulder after eight minutes.
At this point the ball had barely been in the Inverness half.
However, out of nowhere, a curling long-range effort from new County signing Mark Fotheringham beat Antonio Reguero in the home goal, but came back off the bar.
County were settling into the game as the first half wore on, and captain Richard Brittain went close with a 30-yard free-kick which flew narrowly over.
But, just as it seemed the visitors were coming back into the game, they found themselves two down.
Foran broke free of the County rearguard on the right and fed a delightful low pass across goal for Andrew Shinnie to sidefoot home.
As the visitors pressed for a way back into the game as half time neared they left gaps at the back, and Michael Fraser had to save smartly with his legs when Doran was played through one-on-one with the keeper.
The Dingwall side had clearly had half-time words from manager Derek Adams, and carved out the first chance of the second half when a free-kick was awarded at the edge of the box.
And Vigurs curled the ball up and over the wall and into the top corner of the net to give his side a lifeline.
The game raged from end to end in a real derby style, with set-piece opportunities arising from the all-too-frequent blasts of Iain Brines' whistle.
Crosses peppered both goal areas, but defenders had the measure of forwards and chances dried up, although County were having the lion's share of the ball.
County were desperately chasing a leveller, and Rocco Quinn passed up a chance when he shot straight at the keeper from the angle of the six-yard box.
But, for the second match in a row, County conceded late on as Conor Pepper headed a long ball into the path of Doran, who lashed a low volley past Fraser at the near post.