Dick Campbell was sent to the stand as Arbroath crashed to their heaviest defeat of the season to fall behind Kilmarnock in the title race.
Inverness bolstered their play-off hopes with strikes from Shane Sutherland, Ross McAlear and Billy McKay.
And with Campbell ordered off for dissent it was an afternoon to forget as Arbroath lost only their fourth game of the season.
Kilmarnock’s win at Ayr United had dislodged Arbroath from the top the first time in since late December
Former Dundee boss Neil McCann insisted the pressure was now on Arbroath to live up to the hype after boss Dick Campbell admitted they are in a title fight.
That was brushed aside by Campbell and his brother Ian who insisted ‘Arbroath are having the time of our lives.’
But Arbroath were determined to bolster their title challenge with a win against a Caley side still seeking their first victory of 2022.
Arbroath got off to the worst possible start as they fell behind in five minutes after a rare mistake by keeper Derek Gaston.
Gaston has been nothing short of immense for Arbroath this term.
But he misjudged an Aaron Doran corner to allow Sutherland to prod home from five yards.
And things went from bad to worse as they found themselves 2-0 down on 12 minutes.
A superbly-worked five-man move culminated in Reece McAlear drilling beyond Gaston from 18 yards.
Dick Campbell sent to the stand as Arbroath crash to defeat at Inverness
Arbroath almost pulled a goal back on 20 minutes as Michael McKenna’s low drive cracked off the base of the post.
With that, Lichties boss Campbell left his seat in the stand to try and inspire his team from the dugout.
But while they upped their game, Campbell fell foul of referee Euan Anderson and picked up a booking for dissent.
And he was sent off five minutes in to the second half for continuing to complain.
His afternoon got worse in 69 minutes as McKay drilled home the third to complete a comfortable win for the Highlanders.
Teams for Arbroath v Inverness
Inverness: MacKay; Welsh, Deas, Devine, Broadfoot (Duffy 60), Carson, McKay (Pearson 85), Doran (Harper 60), Sutherland, Hardy (Walsh 72), McAlear. Subs: Ridgers; Pearson, Chalmers, Samuels, Hyde
Arbroath: Gaston; Thomson, Colin Hamilton, Little, O’Brien, Gold (Low 68), Chris Hamilton (Ford 75), Stewart (Linn 68), McKenna (Craigen 68), Wighton (Bakare 75), Jack Hamilton. Subs: Antell; Hilson, Donnelly.
Referee – Euan Anderson