Jim Mallinder paid tribute to the support of the Saints fans and chairman Leon Barwell after the stunning win at Saracens.
Mallinder led his team to a sensational 27-13 win at Allianz Park to set up an east midlands showdown with Leicester at Twickenham on May 25.
Their immense effort was inspired by around 2,000 Saints fans who made the trip to Copthall for the clash.
And Mallinder was happy to reward them, as well as Barwell, who has backed the director of rugby through some tough times this season, with a place in the grand final.
“We know that we’ve got the best fans in the country,” said the Saints boss. “They are loyal, they watch us at Franklin’s Gardens, but they do travel in their numbers.
“There are so many faces I recognised who travel all round Europe following the team, so it’s fantastic for them.
“They’ve been to five semi-finals, three with me, and not won one, so this is for them and for the board, who have supported me and the team through a difficult season.
“Leon Barwell has been fantastic. It’s not been an easy season for him, but he’s been really supportive in terms of what he’s done for me and the team.
“We are happy to reward Leon and the board.”
Saints flew into a 17-0 lead at Allianz Park thanks to tries from Brian Mujati and Jamie Elliott, finishing the job with a GJ van Velze try and 12 points from Stephen Myler.
Their ability to beat the regular-season table-toppers had been in doubt before the game, but Mallinder was delighted as his team proved the critics wrong and him right.
“I think we’ve always capable of that,” he said. “We lost to Saracens at Milton Keynes, but it was a very close game.
“We went to Harlequins last week and even though we lost, we lost by three points, at The Stoop. It’s a difficult place to go.
“We know we’re up there and if you’ve seen some of the individual performances from those players it shows we are getting better.
“We’re bringing in a few new players next season, who will hopefully add to the mix, and I’ve got a change in coaching staff as well and all those things we think will help us improve as a team.”