Hull looked set to extend their six-match winning run and take over at the top when they led 4-2 after a scoreless hour of an error-strewn game at the Galpharm Stadium.
But the Giants, who always looked the livelier side, finally got on top in the final quarter, running in tries through Eorl Crabtree (pictured), Luke Robinson and Joe Wardle, with chief architect Danny Brough kicking five goals.
The final score was harsh on Hull but they will have a chance to quickly gain their revenge when the sides meet again in the Challenge Cup at the KC Stadium on Sunday.
Danny Tickle kicked two goals for the visitors.
Wigan followed up their impressive 28-10 win over fierce rivals St Helens with a seven-try demolition over the Wildcats - who crashed to their third consecutive defeat.
Thomas Leuluai, Anthony Gelling and Darrell Goulding all crossed in the first half, with Josh Charnley adding a conversion and a penalty for a 16-0 advantage. In the second half, Wigan ran in four tries with George Carmont (two), Charnley and Goulding all crossing, with Wakefield's only response coming from Kyle Wood.
Steve Menzies and Setaimata Sa each scored a brace of tries, with Lopini Paea, Thomas Bosc, Louis Anderson and Daryl Millard also touching down.
Mickey Higham, Chris Riley and Brad Dwyer went over for the Wolves.
Winger Ryan Hall raced in for four tries but
Ablett, who spent a month on loan with the Broncos in 2005, scored a try in the first half, with Ben Jones-Bishop and Zak Hardaker grabbing a brace each and Brent Webb also touching down.
Kieran Dixon and Luke Dorn were try-scorers for the visitors.
The Bulls followed up their 12-4 Good Friday derby defeat of Leeds Rhinos at Odsal with another impressive display at the Stobart Stadium.
Centre Michael Platt grabbed two tries for the Bulls, while Adrian Purtell, Ben Jeffries, Manase Manuokafoa, Keith Lulia and Craig Kopczak also crossed in a convincing win for Mick Potter's side.
It was a disappointing display from the home side, with Rhys Hanbury scoring their only points of the game with a try.
Tries from Gardner, Sia Soliola, Michael Shenton and Francis Meli proved just about enough to overcome a spirited home side, who scored twice through Brett Ferres and made light of the absence of six first-teamers with a courageous display.
Saints have now won three out of four under the caretaker stewardship of Mike Rush and Keiron Cunningham, yet they will wait anxiously on news of Puletua, who made an early exit holding his left arm, and Gardner.
The latter was clearly in pain as he left the field on a stretcher at the beginning of the second half, having come off worse after contesting a high ball with Josh Griffin.
The result ended Castleford's two match winning run, but, with so many players unavailable, coach Ian Millward will surely be proud of their performance against one of his former clubs.
Scott Taylor was
The Reds looked to be heading for victory, after a 36-10 loss at Huddersfield on Friday, when they led 10-6 until 10 minutes from time.
But prop Taylor charged over twice to seal victory in the mid-table clash following Lincoln Withers' first-half try.
Luke Patten and Ashley Gibson touched down for the hosts.