For Wolves, who have now lost only once in their last 12 visits to Burslem, victory put a morale-boosting end to a sequence of only one point from five away matches that destroyed their hopes of automatic promotion. Vale's valiant attempt to secure the win that would keep their season alive also gave Mark McGhee's side an invaluable rehearsal for the kind of pressure- cooker atmosphere they are sure to encounter in the play-offs.
Not for the first time on the big occasion, Vale were betrayed by their error-prone goalkeeper, Paul Musselwhite. He was at fault when Geoff Thomas, a former Palace captain, put Wolves in front, and again as Mark Atkins restored their advantage within 60 seconds of Tony Naylor's freakish equaliser.
Just as Wolves dominated the first half, so Vale encamped themselves in the visitors' territory for much of the second. The difference was that when Mike Stowell was tested in Wolves' goal he frustrated the swarm of white-shirted attackers with safe handling and one brilliant 85th-minute save from former the Molineux striker Lee Mills.
McGhee, anxious to avenge Vale's victory of last October, held the tactical whip hand until the interval, despite Steve Corica's departure on a stretcher. Vale were regularly outnumbered in midfield and should have fallen behind with less than four minutes played.
Corica's through ball to Thomas caught their defence horribly square. A selfless pass inside to the unmarked Steve Bull appeared to offer the Wolves legend goal No 292 for the club, only for Musselwhite to spread himself and save a scuffed shot.
Bull was soon refused a penalty after he fell under Neil Aspin's challenge, but Wolves were not to be denied. Eleven minutes before half-time, Musselwhite flapped feebly at Simon Osborn's corner, gifting Thomas a simple goal.
Naylor, having already wasted two reasonable chances, promptly contrived to collect his 20th goal of the season with a mid-air volley from 18 yards - with his back to goal to boot - from Allen Tankard's cross.
Almost from the restart, Atkins was allowed to advance to within 30 yard of Vale's goal. The ensuing drive bobbled twice before defeating Musselwhite's dive, bringing the defender his third goal in four games.
Vale's manager, John Rudge, switched to a 3-4-3 formation after half- time; the result was a virtual siege of Wolves' goal. Dean Glover almost scored direct from a corner, while Mills' long-range power twice brought the best out of Stowell, but Wolves held firm.
The Wolverhampton-born Rudge, who has guided Vale to their highest finish since the 1930s, said that he was close to agreeing a new three-year contract. "It's been a brilliant season but we've fallen almost at the last hurdle," he added. "That's the first time we've lost two back-to-back all season."
The Premiership remains firmly within reach for his home-town team. However, it was typical of Wolves' luck with injuries that both Corica and Michael Gilkes may now miss the play-offs because of knee injuries.
Goals: Thomas (34) 0-1; Naylor (40) 1-1; Atkins (42) 1-2.
#Port Vale (4-4-2): Musselwhite; Hill, Aspin, Glover, Tankard; McCarthy, Porter (Koordes, 78), Bogie (Talbot, h-t), Corden (Foyle, 40); Mills, Naylor.
Wolverhampton Wanderers (3-5-2): Stowell; Curle, Atkins, Williams (Law, 51); Smith, Corica (Osborn, 13), Ferguson, Thomas, Gilkes (Venus, h-t); Bull, Crowe.
Referee: W Burns (Scarborough). Booking: Port Vale Glover.
Man of the match: Atkins. Attendance: 13,615.