Midfielder Martin Woods also capped an imperious individual display with the crucial third goal as the Dingwall club ended a woeful run of five straight home defeats in the fixture, claiming a top-six place in the process.
From Northern Ireland international Boyce, though, it was a display of great versatility as he ghosted into deeper positions, linking play and prompting attacks with style and cleverness. His double made it five goals in two derbies and took him back ahead of Celtic’s Scott Sinclair as top league scorer in the Premiership.
County, until a sustained siege towards the end of the match, were the better team. Caley Thistle, ominously for manager Richie Foran, enter the winter break cut adrift in bottom place.
For home manager Jim McIntyre, it was a first derby win in Dingwall since taking charge in 2014.
He said: “I’m delighted. It is very pleasing to get our monkey off our back as we haven’t beaten Inverness since we arrived here.
“We wanted to get back into the top six heading into the break and we set the players that challenge a couple of months back. Apart from the last two results, we have been very consistent and the lads have been superb.
“Inverness had a lot of the game, too, but our chances were better than theirs and we deserved to win.
“Liam is a huge player for us and a clever one who we ask to play in a lot of positions. Wherever he plays he can hurt the opposition as he has football intelligence and he can still get himself into goalscoring positions. He is a class player.”
Inverness arrived at a happy hunting ground seeking to break a clutch of miserable trends. The run of games without a win for Foran’s side was to stretch to ten – the club’s worst spell in ten years. They also sit with their lowest points at this point in a season, in any league, ever.
But there was no disputing the city club’s past dominance in their neighbours’ backyard after 13 wins and five draws in 25 visits. What they didn’t need was to fall behind within one minute and 45 seconds.
Frenchman Christopher Routis saw his corner from the right flicked to the back of the box by the head of Andrew Davies.
Kenny van der Weg was there to whip the ball back across to Boyce who thumped a header off the underside of the bar. Inverness claimed it hadn’t crossed the line but referee Bobby Madden and his assistant were in no doubt.
However, Caley Thistle found a 28th-minute reply. Greg Tansey’s free-kick wasn’t dealt with by the home defence and fell nicely into the path of Carl Tremarco, who knocked a fine diving header past Scott Fox from eight yards.
County midfielder Woods then stamped his mark on the heart of midfield and reignited the Staggies’ threat. First, his 34th-minute free-kick had to be punched two-fisted by Fon Williams before the Welsh keeper parried another powerful strike by the same player.
The ball broke to the far angle of the Inverness box and Boyce, with some ferocity, whipped a right-footed shot into the back of the net to restore the home lead.
Boyce then missed a glorious chance for his second successive Highland derby hat-trick when he fluffed his shot from a Schalk cross to the back of the box.
Crucially, Caley Thistle defender Josh Meekings was off the field and still being bandaged as County picked another hole in the visiting defence. Schalk’s low ball found Woods in space before he beat Fon Williams from ten yards.
Foran’s men kept fighting and it was game on again as substitute Billy King forced a low parry from Fox before fellow sub Alex Fisher followed up to slot Caley Thistle’s second with nine minutes left.
The away side’s siege was incessant – but County held out.
“There’s a bit of a confidence problem running through the team at the moment,” said Foran. “There was a bit of nervousness. But we’re six points off the top six and two wins from where we want to be. 2016 has been a poor performance from me and the players. 2017 will be better.
“The players need the break now. After today they need to go away, get their minds refreshed, come back stronger individuals and find that bit of quality.”