Rory McKeown scored what turned out to be the winning goal in the 48th minute before he was shown a straight red with 15 minutes to go, which will rule him out of the play-off semi-final.
Shaw Lane had earlier equalised through Chib Chilaka after Sean Williams had given the Yellows an early lead from the penalty spot.
The game was littered with yellow cards and two early ones meant that Shaw Lane’s Kieran Lugsden was heading for an early bath on the half hour mark.
It was already 1-1 at that point after Williams had converted a seventh minute spotkick, and Chilaka had buried a sublime header from 14 yards after winning a free kick on the right.
Among the yellow cards was Shaw Lane ‘keeper Eddie Wilcynski, booked for clattering McKeown just outside the box, and from the resulting free-kick Wilcynski saved brilliantly from Williams, who was named in the Evo-Stik Premier League Team of the Year at the weekend.
Half time brought many complaints for the referee, who was barracked by visiting fans from the sidelines as he exited the field.
There hadn’t been much chance for any more controversy before McKeown put the Yellows in front, escaping the clutches of a defender to head home a nice clipped cross from the right by Shaun Beeley.
Beeley was called in to action at the other end, clearing from the off line after Alex Byrne’s shot had been saved by Luke Pilling, but the game was continually interrupted by the referee’s whistle.
The red card for McKeown came on 75 minutes and came with him down on the floor along with a Shaw Lane player, the referee determining that serious foul play had occurred, meaning a three-match ban for the Yellows’ ever present left back.
Shaw Lane pushed for an equaliser late on but in the end it could have been three, had Will Hayhurst not been fouled 50 yards out on his way towards an empty net, left unguarded by Wilcynski having gone up for a corner.
With a play-off berth now secured, the Yellows will now look to finish second – which would guarantee a home semi-final and also the final at home, should they make it.
Their three remaining regular season games come against Halesowen (Home, Saturday), play-off rivals Grantham Town (Away, Tuesday) and Stourbridge (Away, next Saturday).
Warrington Town: Pilling, Carden (McEveley), McKeown, Jennings, Higgins, Goulding, Beeley, Williams, McDonald (Piggott), Kinsella (Bakare), Hayhurst. Unused subs: Leacock-McLeod, Barnes.
Shaw Lane: Wilcynski, Byrne, Serrant (Davies), Kelvin Lugsden, Skelton, Norris, Dyson, Kieran Lugsden, Chilaka (Clayton), Reeves, Williams (Rothery). Unused subs: Gordon, Wright.