Furthermore, the victory restored the Highlanders to a share of top spot after Celtic won 5-2 at Kilmarnock earlier in the day.
Butcher reverted to the line-up he used in Inverness' previous six league games after making one change for the League Cup win over Dundee.
Defender Gary Warren was left out for Danny Devine on Tuesday, but returned to replace his younger counterpart.
Hibernian made three changes from their cup triumph over Stranraer, with Rowan Vine, Abdellah Zoubir and Alan Maybury dropping out.
Kevin Thomson, Paul Heffernan and Ryan McGivern came in for Pat Fenlon's side, who were eager to spoil Caley Thistle's home record.
Both sides traded early corners, with Dean Brill punching one out from under his own crossbar, before a familiar face gave the hosts the lead.
Foran set Graeme Shinnie away on the left flank and his cross was allowed to run across the goal. It reached goalkeeper Ben Williams but he spilled it, with McKay reacting fastest to turn home in the 10 minute.
The visitors' defence then had a let off after James Vincent set McKay away, only for the Northern Irishman's shot to end up wide of Williams' far post.
Hibs' best chance of the first half came when Liam Craig flicked on after being clattered by Josh Meekings. He set Heffernan away but the new signing slashed his effort wide of Brill's goal.
Vincent then went down after a challenge from McGivern and the former Kidderminster midfielder returned the favour with a rash challenge which earned him a caution in the 29th minute.
Vincent's game was brought to an end by a challenge from ex-Chelsea midfielder Tom Taiwo, with Ben Greenhalgh summoned from the bench for an early introduction.
Any balls played into the Inverness box by the away side were nullified by the aerial dominance of Meekings and Warren, the latter throwing himself at everything.
The hosts started off brighter in the second period and nearly capitalised on a slip from Thomson, but the weight on Nick Ross' pass was too strong for Aaron Doran and Williams collected.
Taiwo blazed over from a Craig corner before Ross Draper played McKay in behind Paul Hanlon, only for the Caley Thistle number seven to blast over the bar.
The Highlands side's second goal came in the 59th minute as David Raven set Doran away, his cross headed back across goal by Greenhalgh where the ball broke for captain Foran to drill home.
McKay grabbed his second two minutes later, curling a shot across goal beyond Williams' despairing grasp.
In search of his hat-trick, McKay twice came close with a header from a Greenhalgh cross before his goal-bound effort was blocked by Hanlon.
Fenlon's men wasted a great chance to claw their way back in to the game, Craig skying over from near the penalty spot following Heffernan's pull back.
Inverness nearly grabbed a fourth through an unlikely source in the 72th minute as Raven's floated cross to the back post rebounded off the crossbar.
But Hibs captain Hanlon prevented his side going four down in the closing stages, throwing himself at a Doran shot after Greenhalgh had cut the ball back from the by-line.