The Yellows dominated two thirds of the game needing a win to guarantee a top three finish and broke the deadlock on 56 minutes through Jamie McDonald.
But Halesowen, who only registered their first shot of the game on 70 minutes, fought back to claim an unlikely point thanks to substitute Roland Agbor.
On a gloriously sunny afternoon at Cantilever Park, Warrington set the tempo from the get go and came close to opening the scoring when Sean Williams hit the face of the crossbar with a stunning right foot volley from 25 yards.
A succession of corners came to nothing, as did a couple of free-kicks as Halesowen were pegged for persistent fouling.
It remained goalless at the break, and the Yellows continued to dominate in the early stages of the second half, Gerard Kinsella heading straight at the keeper from Steve Jennings’ ball over.
They finally took the lead when Luke Pilling launched an attack from the back and Mehki Leacock-McLeod took the ball along the byline, the toe of a defender diverting the ball to McDonald, who turned and fired home from six yards out.
A second drinks break of the game enabled Halesowen, who had barely ventured out of their own half, to regroup and they fired a warning shot when Ahmed Ali was denied by the legs of Pilling.
Warrington failed to heed the warning and when Liam Goulding left Jack Kelly’s cross, Agbor got in behind him to side foot past Pilling and earn a point.
A win for Ashton elsewhere means that Warrington enter the final week of the season needing potentially two points to guarantee a home semi-final, and three points to guarantee second place, either of which would set up a home play-off semi-final at Cantilever Park on Tuesday May 1.
Warrington Town: Pilling, Beeley, McKeown, Jennings, Higgins, Goulding, Leacock-McLeod (Davis), Williams (Piggott), McDonald, Kinsella, Hayhurst (Bakare). Unused subs: McEveley, Barnes.
Halesowen Town: Platt, Ekongo, Kelly (Oyenuga), Poscha, Morrison, Charlton, Goddard, Bragoli, Hughes (Monteiro), Ali, BYrnes (Agbor). Unused subs: Lewis, Parsons.