Widnes fought back from an 18-4 deficit to win 32-28 at Bradford - their first triumph at Odsal Stadium for almost 23 years.
Former Bulls winger Patrick Ah Van touched down twice in less than three minutes in the closing stages after Stefan Marsh and Rhys Hanbury had already bagged a brace of tries apiece for the visitors.
Bradford, who have now lost four matches in succession, must have thought their play-off hopes were going to be back on track when they still led 28-16 with barely 20 minutes to play.
Yet the Vikings rallied in impressive fashion, touching down three times in the next 11 minutes to grab their first Super League victory in six outings.
There was no sign of what was to come in the opening 40 minutes, Bradford taking the lead with a try from Adam Sidlow before Keith Lulia accepted a superb off-load from Danny Addy to help make it 12-0 after 16 minutes.
Hanbury got Widnes on the scoreboard but the hosts were soon back on the front foot, Gale's unexpected change of direction allowing James Donaldson to grab for his first try of the campaign.
After Phil Joseph, another old Bull in the Widnes line-up, failed to ground the ball in the act of trying to score, the Vikings did get over again through Marsh, the successful conversion by Jack Owens making it 18-10 at the interval.
The visitors then continued in the same fashion straight after the break, Gareth Hock putting Hanbury in for his second try with Owens' fine touchline conversion closing the gap to just two points.
Quick hands from Brett Kearney and Adrian Purtell enabled Elliot Kear to squeeze over in the corner for a Bulls try and they seemed to have put some daylight between themselves and their opponents when Michael Platt broke free out wide, a magnificent dummy allowing him to race in under the posts.
Yet the Vikings simply refused to go away; full-back Hanbury created a second try for Marsh approaching the hour mark before Ah Van took centre stage.
He first raced 80 metres to score after claiming a Gale kick and then finished off from close range out on the left, Owens' fourth conversion sealing a stunning comeback for Denis Betts' troops.