First-half goals from Tom Pope, Jennison Myrie-Williams and Louis Dodds did the damage as the Valiants moved a point clear of fellow promotion-chasers Gillingham at Victoria Road.
The Gills' home game with Northampton was postponed and Micky Adams' on-song side took full advantage to take initiative in the title race.
Sam Williams reduced the home side's deficit from the penalty spot having been felled by Liam Chilvers, with Pope having earlier given the visitors a fourth minute lead and midfielder Myrie-Williams having doubled the lead five minutes later.
Pope bagged his 23rd goal of the season with a close-range header, Myrie-Williams netting his first goal for five games with a sweet strike.
Dodds latched on to a Calvin Andrew pass to restore Vale's two-goal cushion six minutes before the break.
Scott Doe pulled another goal back for the hosts with a close-range effort with seven minutes remaining to leave a frantic finish, but Vale held on for maximum points.