Pollok secured a 1-0 victory over Neilston in the group stage of the Sectional League Cup.
The homesters’ best chance of the opening period came when David Winters squeezed the ball through to MacKenzie who rolled it past Sinclair only to see it come back off the post.
McBeth brought out the best in Sinclair soon after, forcing the Neilston custodian to make an excellent fingertip save.
Pollok were reduced to 10 men prior to the interval when Tam Hanlon made a dangerous lunge that arbiter Derek Crothers deemed worthy of a straight red card.
The home side threatened with a nice move where Winters teed up Marco Andreoni, but the midfielder failed to find the target.
In the 90th minute Pollok broke the deadlock in what would ultimately be the winning goal of the match.
Darroch’s pass found Winters at the edge of the box, where the striker took a touch before firing a screamer into the postage stamp corner giving Sinclair no chance.