Daniel Holdsworth gained a measure of revenge for Hull’s defeat to Wigan in the Challenge Cup final last weekend as the Black and Whites claimed a last-gasp win.
The visitors led 12-6 thanks to tries from Jason Crookes and Tom Briscoe, with Andy Powell’s first try in rugby league sandwiched in the middle, but Ben Flower and Ryan Hampshire crossed in the closing stages of the first half to give the Warriors a 16-12 interval lead.
The second half was end to end with Wigan leading 26-12 at one stage with tries for Joe Burgess and Iain Thornley, but Hull refused to lie down and hit back with three scores to level it up at 26-26.
Gelling and Briscoe then traded scores and although Sam Powell dropped a goal, two from Holdsworth in the final minutes sealed it for Hull.
The Warriors were missing a number of key personnel with coach Shaun Wane resting no fewer than 11 of his Wembley heroes, meaning youngsters like Hampshire, Powell, Burgess, Lewis Tierney and Dominic Manfredi got the chance to impress ahead of the play-offs.
Hull also made a number of changes from the Wembley defeat with Andy Lynch, Gareth Ellis and Mark O’Meley absent, while talented hooker Aaron Heremaia was suspended.
It was Hull who struck first when winger Crookes used his strength to beat Burgess in the corner to put the visitors in front.
However, the roof almost came off the place in the 22nd minute when rugby union convert Powell crossed for his first try in league to make it 6-6.
It did not take long for Hull to recapture the lead when Jacob Miller and Holdsworth combined to send England international Briscoe in at the corner, Danny Tickle again converting to make it 12-6.
Two tries in two scintillating minutes, however, saw Wigan go 16-12 up. First, Flower crashed over from close range seconds after being held up over the line and straight from the kick-off, Gelling broke down the right and sent Hampshire racing away.
The hosts looked unstoppable and crossed for their fourth try when Burgess was on hand to score his first try for Wigan.
Thornley himself touched down to put Wigan 26-12 ahead before Hull then did to Wigan what the Warriors had done in the first half by crossing for two quick scores.
Crookes touched down for his second try and, two minutes later, Tierney spilled a high ball and again the ball went wide for Crookes to grab his hat-trick try which Tickle converted.
Joe Westerman got the ball down with a close-range drive to level the game at 26-26, but Wigan regained the lead through Gelling, with Hampshire converting.
Powell sloted a drop-goal to make it 33-26, but it was not enough as Briscoe grabbed his second try of the night and Holdsworth then dropped a goal to level it up at 33-33.
A drop-goal attempt by Powell went wide before Hull went right up the other end and won it with their own as Holdsworth saw his kick sail between the posts.