Vale took the lead when Ryan Burge's pass fell to Louis Dodds to prod home and soon after Tom Pope added a second, before home substitute Kieran Agard was on target to set up an anxious finish.
Gillingham saw their lead trimmed after losing 1-0 at home to Barnet with Jake Hyde's first-half strike settling the contest at Priestfield Stadium.
Cheltenham bounced back from their surprise 4-1 defeat at Rochdale with a 4-0 drubbing of Wycombe.
Goals from Jake Taylor, Jeff Goulding, Darryl Duffy and Jermaine McGlashan kept the Robins in third place.
Promotion-chasing Southend extended their unbeaten run to 14 matches with a brace from Gavin Tomlin helping them beat his former club Dagenham and Redbridge 3-0 with Kevan Hurst hitting the third.
Bradford remain just adrift of a top-four berth after defeating Accrington Stanley 2-1 thanks to goals from Garry Thompson and Alan Connell that sandwiched a strike by Rommy Boco.
Oxford made it five games unbeaten with an impressive 3-1 victory at promotion-chasing Exeter.
James Constable took his tally for the season to nine with goals either side of half-time and Peter Leven added the third before Jamie Cureton bagged from the penalty spot for the Grecians.
Three second-half goals from Drew Talbot, Danny Whitaker and Tendayi Darikwa gave Chesterfield a convincing 3-0 win over York, John Ward earned a point on his managerial return to Bristol Rovers after the Pirates left it late to earn a 2-2 draw at fellow strugglers Aldershot, with Eliot Richards climbing off the bench to snatch a point.
Michael Hector's stunning strike put the home side ahead, David Clarkson and Craig Reid then exchanged successful spot-kicks, only for Richards to drive home the leveller with three minutes to spare.
Teenage debutant Tyler Harvey smashed home a dramatic late equaliser for Plymouth as they drew 1-1 with Devon rivals Torquay at Home Park.
The 17-year-old youth product equalised with a superb left-foot shot on the spin from the edge of the box after Aaron Downes had given Torquay the lead.
Burton surrendered a two-goal lead against Rochdale but still managed to pick up a 3-2 victory.
Goals from Billy Kee and Calvin Zola put the Brewers in charge, but Peter Cavanagh and Bobby Grant levelled the score before Kee hit the winner.
Striker David Ball's sixth goal of the season handed Graham Alexander his first victory as Fleetwood boss as they beat Morecambe 1-0.