CONNOR Bell hit the only goal of the game as Caley Thistle saw off Falkirk to reach the semi-finals of the Irn-Bru Cup.
In this all-Championship contest, ICT also broke a new club record for shutting out opponents for more than the 617 minutes set three years ago.
These have been good times for Inverness CT.
Manager John Robertson had guided them to six games unbeaten, all without leaking a goal.
He was rewarded by winning the sponsor's manager of the month award on Thursday, with defender Carl Tremarco winning the player prize for October too.
The Caley Jags were forced to make one change from their 0-0 league draw at Livingston last weekend.
Jake Mulraney was on Republic of Ireland under-21 duty, so Alex Cooper gained a call-up into the team.
Kevin O'Hara was out of contention for the visitors following his eight-match ban for taunting Dunfermline's Dean Shiel's for having one eye.
The changes from their 1-1 Championship draw against Dunfermline last week were Nathan Austin, Alex Harris and James Craigen all gained promotions to the starting 11.
ICT and Falkirk had played twice this season before tonight, with Falkirk winning 2-0 in the Betfred Cup and Paul Hartley's first game in charge of the Bairns recently ending goalless.
Falkirk had a couple of early chances with Myles Hippolyte firing a shot wide then Alex Harris saw his cross just diverted past for a corner, which was well defended.
Caley Jags responded as defender-turned midfielder Joe Chalmers went close with a deflected drive from distance, which also led to a corner, which came to nothing.
Hippolyte shot over the top for the visitors after a mix-up between goalkeeper Mark Ridgers and Coll Donaldson almost led to disaster.
John Baird almost opened the scoring against his former club, but keeper Robbie Thomson saved his shot with his feet to keep it blank. It all stemmed from a Cooper cross from the right.
Then, it took a Donaldson goal-line clearance to prevent Hippolyte from scoring when he struck amid a packed penalty box for Falkirk.
Harris then weaved his way into the box and another inviting delivery just missed the navy shirts rushing in to attack it.
Just after the half hour mark, play was halted after a clash of heads between Falkirk's Aaron Muirhead and Tremarco. After treatment thankfully, they both resumed.
Four minutes before the break, Thomson pulled off a fine diving save to keep out a swerver from ICT's Iain Vigurs to ensure there was no opener for the Highlanders.
Cooper almost put Caley Thistle ahead early in the second half, but his looping header was touched over the top by Thomson.
When the clock ticked by the 50th minute mark, ICT set a new club record by keeping out opponents for more than six and a half matches set in 2014 when they didn't concede for a total of 617 minutes.
They last leaked a goal in the 2-1 defeat against Dumbarton in the league on September 23.
Just after that, Caley Thistle appealed for a spot-kick when Conrad Balatoni seemed to trip Baird in the box, but referee Euan Anderson waved play on.
However, they were in front with a fine goal after 57 minutes when Raven whipped in a cross, Baird flicked it on and Connor Bell lashed the ball home from 10 yards for his fifth of the season.
He was on target again not long after that with a drive from 25 yards, but Thomson got down to clutch it.
Bairns pressed for leveller, but Caley Jags stood firm to book their place in the last four.
The draw for the semi-finals which will also include Northern Ireland's Crusaders, Dumbarton and the winners of Sunday's tie between Welsh league side New Saints v Queen of the South takes place on Tuesday.
Caley Thistle return to Championship action on Tuesday, November 21 when they host rock bottom Brechin City.
Inverness CT: Ridgers, Raven, Tremarco, Chalmers, Polworth, Baird (Oakley 79), Vigurs, Bell (Calder 86), Cooper (Doran 71), Mckay, Donaldson. Subs not used: Cameron Mackay (GK), Warren, Daniel Mackay.
Falkirk: Thomson, McGhee, Muirhead, McKee (Loy 63), Austin (Dunne 71), Hippolyte, Longridge, Harris, Balatoni, Craigen (Blues 84), Watson. Subs not used: Mutch (GK), Grant, Gasparotto, Gallacher.
Referee: Euan Anderson.