Wigan overturned the odds to beat Manchester City at Wembley and Northampton director of rugby Jim Mallinder took that as proof that anything was possible for his underdog side at Allianz Park.
Northampton, who had finished 12 points behind table-toppers Saracens in the regular season, raced into a 17-0 half-time lead with tries from Brian Mujati and Jamie Elliott.
But no-one in the Saints changing room was complacent at the interval because, only two years ago, Northampton led Leinster 22-6 in the Heineken Cup final and went on to lose 33-22.
Owen Farrell kicked two penalties to keep alive any faint hopes of a Saracens comeback - but they were quashed when GJ Van Velze scored Northampton's third try just before the hour. Saracens did engineer a consolation try from Duncan Taylor when Elliot was in the sin-bin but it was the Saints who marched on to Twickenham.
Asked about the inspiration he drew from Wigan's FA Cup win, Mallinder said: "They (Saracens) finished first and we were fourth. They were unbeaten here and we hadn't beaten them all season. We hadn't beaten a top three team and they clearly were the favourites.
"But the favourites don't always win. I had a number of people reminding me of that after the Wigan-Manchester City game. We have had an up and down season. We have come in for a great deal of criticism along the way, a lot of that quite rightly.
"We have not beaten a top three team all season. We have known that. We have been reminded so many times. The players have responded. They have known they are good enough."
Mallinder decided not to mention the Heineken Cup final misery at half-time but he was thinking it, and so were the players. Tom Wood revealed it had been a key second-half motivator. "We talked about that at half-time, that 'we have been in this position before and let it slip so it was a huge motivation and it was on our minds," Wood said.
Saracens director of rugby Mark McCall said: "It is a massive disappointment. We gave ourselves a mountain to climb at half-time. Northampton put us under a lot of pressure especially in that first half and we made a lot mistakes."
- Sports & Recreation
- Jim Mallinder