It was a night to forget for the Dons, who lost four goals and a player, as well as the opportunity to face the Clydesdale Bank Premier League leaders at Hampden on March 16.

Darren Dods, Christian Kalvenes, Craig Conway and Morgaro Gomis were all on the scoresheet as United romped to what was a convincing victory in the end, after Andrew Considine had given the Dons the lead early on.

Jim O'Brien, Danny Swanson and Danny Grainger were all cup-tied for United, while an earlier appearance in the competition for the Tannadice side denied Stuart Duff the opportunity to turn out for Aberdeen.

For everyone else though, the waiting was finally over. This tie initially fell victim to the weather last midweek but, having been given the go-ahead tonight, both teams attacked the match at a frantic pace early on.

Neither side had reached the final of this tournament since Aberdeen's defeat to Celtic back in 2000 and both teams were well aware that was all about to change for the team who came out on top at Tynecastle this evening.

United were quickest out of the traps. Mark de Vries, making his first start since his return north of the border, nodded David Robertson through on goal early on but he was denied the opener by a timely intervention from Zander Diamond.

Noel Hunt then drove a powerful effort into the side-netting after collecting a Kalvenes ball on the right wing as Craig Levein's men attempted to crank up the pressure.

It was Aberdeen's cue to haul themselves into the game and Josh Walker and Barry Nicholson both tried their luck with long-range efforts that did little to trouble Lukasz Zaluska. It was not long, though, before he was plucking the ball out of the back of the net.

Nicholson whipped a corner into the box to the head of Diamond, whose effort was parried by the United goalkeeper. The ball broke kindly to Considine, who was the unlikely claimant of the opening goal when he stabbed home from close range with 19 minutes gone.

If Considine's goal was a collector's item, so, too, was Dods' when he restored parity just four minutes later. The Dons fans were still celebrating when he threw himself in front of Kalvenes' free-kick and directed a header past the helpless Jamie Langfield.

Like Considine, it was only his second goal of the season so it was probably asking too much for the defender to claim another shortly before the break when he glanced a header from Craig Conway's cross just wide of the upright from close range.

Switching ends proved problematic for Dons keeper Langfield in the second half when the game was briefly halted after he was pelted by missiles, including a plastic cup of tea, by United fans behind his goal.

Those supporters were celebrating with 59 minutes gone. A poor clearance from Langfield gifted United a corner, which was duly delivered into the box by Conway and Kalvenes rose above everyone else to nod home from 12 yards.

There appeared to be no way back for Aberdeen when they lost another goal and a man within three minutes.

A long ball from Zaluska was pounced upon by De Vries. He nodded into the path of Conway who did well to shrug off the challenge of Diamond before rounding the goalkeeper and keeping his cool to slot home.

The night deteriorated further for the Dons when Lee Miller was then sent packing with 23 minutes remaining for a second yellow card for a late tackle on Dods.

The final nail in the coffin arrived after 75 minutes and came courtesy of Aberdeen skipper Scott Severin. His dreadful pass back to Langfield was woefully short, allowing Gomis to slide in and divert the keeper's vain attempt at a clearance over the line.