South Shields suffered defeat 3-2 against champions Tamworth to take the play-offs to the final day in the Vanarama National League North.
Mackenzie Heaney's first-half free-kick gave life to Shields after conceding two early goals.
Michael Woods equalized for the Mariners but it wasn't enough as Tamworth reclaimed their lead.
Elliott Dickman's Shields were looking to build upon a 7-0 triumph over Bishop's Stortford last time out.
A trip to the newly crowned champions was the final task away from home for Shields to overcome to remain in with a chance of qualifying for the play-offs.
Shields fielded an unchanged side from the side that put Stortford to the sword,
Tamworth manager Andy Peaks four changes to the side that secured promotion against Warrington, as top-scorer Kyle Finn was dropped to the bench.
The Lambs took the lead in the 5th minute through Chris Wreh's header from close range after Tamworth's first corner of the game.
Nathan Tskikuna managed to take the ball from Myles Boney in the 21st minute and finish from a tight angle to make it 2-0.
Mackenzie Heaney gave hope to Shields in the 31st minute as he converted directly from a free-kick into the top corner.
After the interval, it was anyone's game as both sides pushed on for the next goal.
Shields pegged the champions back in the 57th minute through Micheal Woods who was quickest to the ball and beat Jas Singh in goal.
The hard work of Shields was cancelled out by Nathanial Knight-Percival's 71st-minute strike that managed to beat everyone in the box and into the net past Boney.
Shields pushed for an equalizer but were denied by some great defending by Tamworth.
The defeat for Shields sees them drop to 7th place, only in a play-off spot on goal difference.
The fate of the Mariners will be decided on the final game-week of the season at home to Southport.
South Shields: Boney, Hunter (Clarke 79), Briggs, Broadbent, Adams (C), Smith, Heaney, Jenkins, Woods, Blackett, Stephenson (Martin 72)
Unused subs: Abbey, Sloan, Gomes
Goals: Heaney (31'), Woods (57')