The Wanderers produced a fine performance to beat holders Harlequins 39-30 and book their place in the Aviva ‘A’ League final.
Tries from Howard Packman, Ethan Waller, Alex Woolford, GJ van Velze and Matt Williams saw the Saints shadow squad maintain the winning feeling at Franklin’s Gardens on Monday night.
Sam Olver added 14 points with the boot as Quins surrendered a 16-14 half-time lead, given to them by two tries from Sam Smith and two penalties from Ben Botica.
The away side almost mounted an unlikely comeback late on, with tries from James Chisholm and Louis Grimoldby bringing them back to four points behind having been 34-16 down.
But Williams scored late on to ensure the Wanderers held on and they will now face Bath, who won their semi against Sale Jets 39-21, in the final at the Gardens on December 16.
The green, black and gold will have home advantage courtesy of scoring the most tries in the group stages of the competition.
And they will fancy their chances of finishing a fantastic campaign with a trophy, having won five of their six ‘A’ League games, scoring 30 tries in the process.
A strong squad was named for the visit of an equally talented Quins outfit, who fielded the likes of former Saints prop Paul Doran-Jones and experienced second row Nick Kennedy.
It was the Wanderers who showed their teeth first as Olver landed a penalty after Teimana Harrison was not released in a tackle.
It was to get worse for Quins four minutes later as Botica missed touch with a penalty, giving back row forward Williams the chance to charge forward and offload to Packman, who did the rest.
Olver missed the conversion but made amends by landing a penalty before Botica replied at the other end.
The Quins No.10 added another three-pointer and Quins were level soon after as Smith scored an interception try.
The wing was on the money again seven minutes before the break as he finished off a move dominated by a powerful maul by the visiting pack.
But Olver cut the deficit to two points before the break with another penalty and the Wanderers were at it from the off in the second half.
Waller got them motoring on 46 minutes with a drive towards the line, carrying three Quins players with him as he touched down.
And, eight minutes later, some good work from scrum-half Alex Day pinned the away side back, giving the Wanderers the platform to maul their way over the line, with second row forward Woolford the man profiting.
Van Velze added a fourth try to his team’s tally and a fifth to his personal ‘A’ League haul this season by powering over in the corner following a good move from a lineout.
Olver added a penalty after some fine carrying from Harrison before Quins picked themselves up off the floor to get back in the game.
Chisholm dived over before Grimoldby brought them to within four points with his side’s fourth score.
But the impressive Williams ensured there would be no late heartbreak for the Wanderers, picking up the ball after some strong work from Rob Verbakel to finish the job.
Wanderers: Diggin; Packman, Stephenson, Dickson, Skelcey; Olver, A Day; E Waller, McMillan, Denman, Woolford, Verbakel, Williams, Harrison, van Velze (c).
Replacements: Marshall, Warren, Parkins, Harry, Betts, Glynn, Mallinder, Hooley.
Harlequins: Lindsay-Hague; Walker, Marchant, Molenaar, Smith; Botica, Stuart; Lambert (c), Allen, Doran-Jones, Merrick, Kennedy, Trayfoot, Spinks, Chisholm.
Replacements: Cobb, Marfo, Mayhew, Treadwell, Wallace, Burns, Grimoldby, Katz.