In the first ever meeting between the two sides, Khalsa came out of the blocks firing on all cylinders and Lee Chilton headed over the bar after three minutes.
The visitors had their first sight of goal on 20 minutes, Josh O’Grady shooting wide and four minutes later Carlo Franco cleared a shot off the line on 24 minutes as visitors got a strangle hold of the game.
Chances were few and far between and the first half ended goalless.
The second half continued in much the same vein. Craig Bannister shot over the bar on 49 minutes and Marvin Nisbett had a good chance on 65 minutes but headed over after Dave Meese flicked on Franco’s long throw.
The game exploded into life right at the end and could so easily have gone differently. Substitute Tim Jackson saw his 90th minute free-kick cannon back off the post and despite a whole host of bodies in the box, Khalsa were unable to force the ball home.
United then broke on the right and delivered the sucker punch thanks to the quick thinking of Williams, leaving the home side devastated and defeated.
Sporting Khalsa return to action on Wednesday, facing Westfields in the league (kick off 7.45pm), before the big FA Cup game on Saturday at home against Romulus (3pm).
Sporting Khalsa: Tom Turner, Carlo Franco, Joe Rogers (Tim Jackson), John Hill, Tes Robinson (captain), Lee Chilton, Dave Meese, Elliott Turner, Craig Bannister (Michael Nelson), Simeon Townsend (Danny Ashton), Marvin Nisbett