Jon Stead scored a late penalty for Notts County as they managed to grind out a 1-0 win over spirited Port Vale at Meadow Lane.The Magpies striker converted from 12 yards with just four minutes remaining of a pulsating encounter, having been shoved in the back by Marcus Harness.It was enough to break the resistance of goalkeeper Ryan Boot who had kept Vale from conceding in the first half with two fine saves to deny Jonathan Forte and Ryan Yates.Vale had their moments, with Harness denied twice by two desperate blocks from the hosts' committed defence.Substitute David Worrall also should have done better when he was completely unmarked from a Tyrone Barnett cross but he headed tamely at Ross Fitzsimons.Home substitute Callum Saunders also squandered a great opportunity when he was left alone from a ball into the box but headed wide of the far post.But Stead had the final say in what was a crucial win for the Magpies, who remain second in the table.