The Valiants, who made eight changes from their goalless draw with Barnsley, were ahead after just three minutes when Ryan Croasdale struck with a low drive from Onel Hernandez’s pass.

Archer then sensationally doubled the Valiants’ lead in the 16th minute with a free-kick from 25 yards that flew into the top corner.

Peterborough were back in the game after 31 minutes when James Dornelly made the most of slack marking to sweep in Matthew Garbett’s corner.

However, Vale restored their two-goal cushion in the 59th minute when Archer repeated his earlier trick with another wonderful dead-ball strike that left Peterborough goalkeeper Alex Bass grasping at air.

Despite the win, the third-from-bottom Valiants are still 12 points adrift of safety, with their survival hopes extremely slim, while the Posh stay four points ahead of the drop zone with four games of their season remaining.