Spalidng United will contest the play-off final in Division One South Of the Evo Stik Northern League.
The Tulips will travel to favourites Witton Albion on Saturday (April 29) with the winners promoted to the Premier Division.
Spalding earned their tilt at glory with a thrilling 3-2 play-off semi-final win over Stocksbridge Park Steels at the Sir Halley Stewart Field last night (April 25).
A classy extra-time strike from substitute Jonny Lockie turned out to be the winning goal of a pulsating clash between the teams that finished second and third in the division.
Twice the visitors had hauled themselves level after a penalty from Matthew Varley and a firm header from Lee Besson had given Spalding the edge, but there was no coming back a third time.
It will be tough for Spalding at Witton who finished 17 points clear of third place in the regular season, but the Tulips did draw 2-2 there earlier this month.
Witton beat AFC Rushden & Diamonds 1-0 in the other semi-final last night.
Deeping Rangers were presented with the United Counties Premier Division runners-up trophy before their final home match of the campaign last night. They celebrated with a 4-1 win over Harrowby courtesy of goals from Tom Waumsley, Tom Smith, Scott Coupland and Scott Mooney.
Tuesday, April 25
EVO STIK NORTHERN LEAGUE
Division One South play-off semi-final
Spalding 3 (Varley, Beeson, Lockie), Stocksbridge Park Steels 2
UNITED COUNTIES LEAGUE
Deeping Rangers 4 (Waumsley, Smith, Coupland, Mooney), Harrowby United 1