Time was ticking away when, with Arsenal 1-0 up and seemingly home at 3-2 on aggregate, substitute Mido rose to flick home Jermaine Jenas free-kick to level it all up.
Having looked composed all night, the Gunners were suddenly rocking for a short spell, but that second chance didn't arrive and the home side took control of extra time, with goals from Aliadiere and an own goal from Pascal Chimbonda seeing them home 3-1 on the night, 5-3 on aggregate.
Back to normal time and Robbie Keane got himself beyond the red line after ten minutes and found himself alone in front of Manuel Almunia following a finely picked out throughball from Michael Dawson. Being unchallenged other than the advancing Spaniard might just have unnerved Robbie who ended up steering his effort tamely at the keeper. It was a real chance though.
Three minutes later the home side thought they were about to hold sway when Kolo Toure swapped passes with Denilson before the Brazilian drilled in a shot that Paul Robinson failed to hold and the following up Toure looked set to tap home, but he caught the ball with his studs and his attempt bounced narrowly wide of the post.
Jeremie Aliadiere made a smart turn in our area from a Justin Hoyte cross and just dragged his shot slightly past Robinson's right hand upright, but as the half progressed and became more cat and mouse, the goalkeepers were less and less involved. It wasn't exactly fire and brimstone stuff considering the traditional nature of these occasions.
Steed Malbranque did come pretty close before the interval when he connected with a Hossam Ghaly cross from the right and nodded wide.
While the scores remained level we were edging ahead in the card count and had collected two to their one before half-time from hefty challenges made by Jermaine Jenas and Anthony Gardner.
Five minutes into the second half Theo Walcott was a little too close to comfort with a chip from the right corner of our penalty area. There was then a flash point when Ghaly was bundled over by Armand Traore and reacted with a lunge on Philippe Senderos. Abou Diaby and Ghaly then came dangerously close to getting into trouble in the aftermath of the incident.
With not coming any closer to breaking through our defences, Arsenal introduced the first of their experienced number from the bench in the shape of the Czech Tomas Rosicky, quickly followed by Gael Clichy - as a direct result of Traore being stretchered off.
Summing the game coming up to the 70th minute was best done by a stat that flashed up on a monitor in the press box - just one shot on target.
Our first change came with 17 minutes remaining and it was Ricardo Rocha for Gardner, with Martin possibly worried about the potential for another booking.
The sucker punch with just 12 minutes left on the clock when Robinson made a reaction block from a Rosicky drive and the ball ended up back with the same player who then split our defence to allow Adebayor through on goal and he proceeded to slot past Robinson.
The response when it came seven minutes later was emphatic and joyously received behind the goal it was scored. A Jenas set piece from the left was met by the head of substitute Mido and Almunia was left clutching thin air as the ball whizzed past him.
With five minutes stoppage time just underway Mido nearly snatched it when he refused to be shoved off the ball on the edge of the area and sidefooted a curling effort that beat Almunia, but also just cleared the post. Robinson then needed strong palms to deal with a powerful hit from Denilson.
Robinson was soon forced into an even better save from Toure before Dawson was left to clear his lines. The 90 minutes was then up.
The first 15 minutes of extra time passed without incident until, just before the whistle, Rocha attempted a low header from a Denilson cross and the ball travelled as far as Aliadiere, whose shot defeated Robinson to his left.
It was a stomach-churning blow in a contest we were more than in.
It got worse half way through the second 15 minutes when Rosicky wriggled free inside the area and crashed in a shot that went in via the inside of the post and Chimbonda.
Mido's late goal gave us hope, but Arsenal made sure it was Carling Cup heartbreak with two goals in extra time to win Wednesday night's semi-final at the Emirates Stadium.