For the second successive week St Kilda has snatched victory from the jaws of defeat courtesy of one of its youngsters to reach the NAB Cup final for the second time in five seasons.

After beating reigning premiers Geelong with a late goal from rookie Jack Steven last week, this time it was second year player David Armitage who was the hero with a controversial goal in the final minute to hand the Saints a thrilling 1.12.13 (94) to 1.12.10 (91) victory over a gallant Essendon at Telstra Dome.

The Saints, winners of the NAB Cup in 1996 and 2004, will now play Adelaide or Hawthorn at either Telstra Dome or AAMI Stadium next week in the pre-season decider.

It was a heartbreaking end to a promising pre-season campaign for the Bombers under new coach Matthew Knights as they came desperately close to their first grand final appearance in this competition since their last premiership year in 2000.

When Courtney Johns goaled from a great Mark McVeigh pass with just over three minutes left the Bombers looked home, particularly after former Cat Charlie Gardiner missed a set shot from 40 metres out to leave the Saints trailing by three points with only two minutes left.

But the Saints surged again and when Essendon big man Jason Laycock was too slow to get rid of the ball and tackled it led to a loose ball, which Bombers' youngster Angus Monfries promptly dived on.

He was then set upon by not only by Armitage but also two team-mates who dived on top of him in an attempt to force a ball-up.

But umpire Matt Stevic ruled Monfries had made no attempt to get rid of the ball and while the decision appeared harsh it was technically correct under the current rules and Armitage made no mistake from the resultant free from just 20 metres out.

The Bombers had one last chance to snatch victory but former Geelong ruckman Steven King - who was the best big man on the field all night in a promising sign for the Saints - made a tremendous spoil on Laycock as he looked set to mark within goalkicking distance.

It was a good night for the Saints new recruits because apart from King, former Swan Adam Schneider also had a big hand in the win 20 possessions and a goal.

The Saints' victory was even more creditable considering they were not only without star forwards Fraser