John Robertson's side were reduced to ten men just after half time and that swung the pendulum towards the visitors. Jordan White headed against the post in the first half, but Liam Polworth was red carded three minutes after the break. Despite the numerical advantage, Inverness made United work hard for their break and it came in the 78th minute after substitute Nicky Clark hit the post and Paul McMullan slotted in the rebound. Harsh on Inverness who had battled really hard to make up for the loss of Polworth.
Only half time in the tie though and still all to play for at Tannadice where we won 2-1 in the Scottish Cup. United will know they will be in for a hard time and our lads will give it everything, similar to tonight. Great effort with Shaun Rooney outstanding. Jamie McCart was immense at the back and Mark Ridgers assured dealing with early crosses. Aaron Doran looked lively early on before fading in the second half when we were down to ten.
The winners over the two legs will face either St Mirren or Hamilton Accies.
On BBC Sport:-
Inverness CT manager John Robertson: "We don't feel it's a red car. It could easily have sufficed with a yellow. For the referee to change the whole complexion of the game on that incident - we feel hard done by.
"I can understand why he's given it - we know the laws of the game. It is what it is. We are 1-0 down. We've won at Tannadice before. We go down there full of confidence."
Dundee United manager Robbie Neilson: "Pleased with tonight but by no means are we on easy street now. We've got a tough, tough game coming up.
"The sending off has a bearing on the game. I've been delighted with Paul McMullan since I came in. He's got potential to really go far in the game because he's got that pace and he's got the fitness levels as well."
Inverness were without the injured Tom Walsh and Carl Tremarco, with Anthony McDonald and Kevin McHattie starting. Dundee United had a clean bill of health after a ten day break whilst Inverness had battled through two tough games against Ayr United to get here.
It was a wonderful sunny evening as United took to the park in front of a healthy and vociferous travelling support of over 1,000, welcoming their team into the Caledonian Stadium as if they had won the world cup itself. The North Stand was sparsely populated and like a morgue in comparison. Apathy rules in the Highland capital I'm afraid.
The visitors kicked off and Coll Donaldson was immediately the target of their small minded section who took every opportunity to have a go at him as he won a free kick inside the first minute. Get over him Arabs.
Liam Polworth fired a cross into the box which Siegrist parried clear as we made our intentions clear, but it was Mark Ridgers that had to make the first save after Peter Pawlett fed Osman Sow and Ridgers saved down low as the big striker smothered his shot from a good position.
Polworth headed on to Joe Chalmers and the Dingwall target fired just wide as the game ebbed and flowed in the evening light.
In the 23rd minute, Jordan White almost broke the deadlock as his header back across the keeper bounced off his right post, Siegrist beaten but the rebound was smuggled clear. The hosts were getting on top and a poor clearance by the United keeper almost led to a chance for White and Polworth, but it was snuffed out for a corner. From the clearance, the energetic Shaun Rooney fired a shot from Richie Hart area a couple of yards over the bar.
United's main threat was Paul McMullan, he of dubious diving decisions and errant hand balls. Tonight he was simply playing football and his pace was causing Kevin McHattie a torrid time. Ridgers had to be alert to catch a high shot towards goal from the wee neckless hunchback as he demonstrated his menace. Pavol Safranko shot wide from the resultant corner.
Siegrist gathered a White header as we pressed for the opener, but it lacked any power to beat the keeper.
To the delight of the Dundee United fans, Coll Donaldson was booked for felling Pawlett, the biggest cheer since the teams came out onto the park. Right on half time he foolishly gave away another free kick on the edge of the box, the forward heading away from the box but Coll tested the patience of the referee and brought another round of soccer rage from the vising fans.
The free kick came to nothing fortunately and that brought an end to a high tempo first half with both teams having a go.
Half Time 0-0
Safranko stayed in the dressing room after the break with Calum Booth replacing him. It made Donaldson lighter as the big forward had now left his pocket.
Three minutes into the second period and disaster for Inverness . As Polworth tried to flick his toe towards the ball on the edge of our box, Mark Connelly lowered his head and made a meal of going down and clutching his face. Surely an ambulance would be called. No, instead of blue lights, we got a red card for Polly who could have made his final contribution for the Caley Jags. Surprisingly there seemed to be little if any damage to the Arabs player who was on his feet soon after. The free kick came to nothing, but the red card changed the dynamics of the game.
Aaron Doran and big Jordan linked well with White's shot blocked as he pulled the trigger, close call for United as the ten men continued to cause them problems. None moreso than the marauding Shaun Rooney who was like a duracell bunny all night.
United were beginning to wear down Inverness, gradually, and substitute Nicky Clark tested Ridgers with a low drive. Cameron Harper had replaced a tiring Doran by now for the hosts.
Ten minutes after coming on, the fresh legs of Clark saw United take the lead. McMullan benefited from a McHattie headed clearance that rattled off his chest, he then toe poked the ball to Clark and he fired a low shot back across the keeper from around the penalty spot. It cannoned off the left hand post of Ridgers and as we failed to react quick enough, McMullan buried the ball low into the net off the opposite post. Incredible set of circumstances and very harsh on the ten men of Inverness who had still looked dangerous on the break.
Charlie Trafford had a shot saved and Callum Smith shot over as the game just ran away from us, but what an effort from the guys, just a pity so few bothered to turn up to watch the game and preferred watching on TV or washing their hair. Everything to play for at Tannadice and United will be wary of us.
Red card or no red card? Well, if you ask the referee to make a decision and put him on the spot then there's every chance they will get it wrong and ruin what was a highly entertaining game up to that point. Many pundits (and Robbo) reckon a yellow would have sufficed, but we are talking third rate Scottish referee's here. Meh!
No failures in the red and blue of the Caley Jags who were best served by sponsors MotM Aaron Doran until he tired, Jamie McCart who continues to impress and was a rock at the back, Charlie Trafford who just keeps getting better and the guy that impressed me with his Tokelyesque marauding runs down the flank, Shaun Rooney.
Unfortunately United were best served by the three that mattered most, Nicky Clark, the menacing sprinter Paul McMullan, and Siegrist's right hand post. Doh!
Here's the action from the SPFL site
And here is Robbo................