Caley Thistle’s hopes of a return to the Scottish Premiership were ended by Dundee United in controversial circumstances at Tannadice.
United, who won the first leg 1-0 thanks to a late Paul McMullan strike at Caledonian Stadium, doubled their advantage in first-half injury time when Nicky Clark converted from the penalty spot.
Inverness manager John Robertson was sent to the stands for his protests to referee Kevin Clancy and the misery was compounded nine minutes into the second half when Osman Sow made it 2-0 to Dundee United and 3-0 on aggregate when he fired home to end any hopes of an Inverness comeback before Pavol Safranko added another with 10 minutes remaining.
The Tangerines will now face either St Mirren or Hamilton Accies in the Scottish Premiership play-off final with the first leg taking place on Thursday.
Tom Walsh, who missed the first leg with a hamstring injury, stepped in for the suspended Liam Polworth following his red card for a reckless challenge on Mark Connolly.
Dundee United manager Robbie Neilson made two alterations with Calum Butcher and Pavol Safranko replaced by Rachid Bouhenna and Nicky Clark.
Caley Thistle, who were hoping to emulate their 2-1 Scottish Cup victory at Tannadice in March, settled into the game nicely but it was the hosts who had the first shot on target with Peter Pawlett’s low drive comfortably handled by Mark Ridgers.
Benjamin Siegrist was called into action at the other end in the 14th minute when he displayed smart reflexes to claw away a deflected Walsh effort.
Jordan White was inches away from connecting with a sumptuous cross into the area from Kevin McHattie before Charlie Trafford dragged a shot wide from just outside the area.
The visitors continued to look the more threatening with White’s powerful drive bravely blocked by Connolly before the Caley Jags forward nodded over from the resulting corner.
The United crowd were growing increasingly nervous and were fearing the worst when Brad Mckay’s searching pass sent Aaron Doran through on goal but the Irish winger could find no way past Siegrist.
After enjoying the best of the half, Caley Thistle were dealt a major blow in first half injury time when Brad Mckay was adjudged to have handled a Pawlett shot by referee Kevin Clancy and Clark made no mistake from the spot.
The decision appeared harsh on Mckay with Caley Thistle manager Robertson forced to watch the second half from the stands as a result of his protests to referee Clancy during the break.
Things went from bad to worse for Inverness after 54 minutes when McMullan crossed for Sow to smash home his first goal for Dundee United.
The hosts almost grabbed another in the 66th minute when McMullan found substitute Safranko unmarked but his effort bounced back off the post.
Clark was guilty of an astonishing miss two minutes later when he hit the post with an open goal at his mercy following a dreadful mix up between Mckay and Ridgers.
Siegrist made another fine stop to keep out a Jamie McCart header as Caley Thistle pushed for a route back into the game.
But it was United who netted again when Safranko added a third with 10 minutes to go with a cool finish after superb link-up play by Sam Stanton.
