Two tries in seven second half minutes overturned a 6-2 interval deficit as Warrington Wolves were pipped 12-6 in a tense Grand Final at Old Trafford.
Josh Charnley scored the winning touchdown in his final game of rugby league before switching codes with Sale.
Warrington, who finished top of the table, were left still waiting for their first championship since 1955.
Wigan’s victory means the three trophies this year have been lifted by different teams, with Hull winning the Challenge Cup and Warrington the league leaders’ shield.
Wigan took an early lead through a Matty Smith penalty goal and created a series of first half chances, but trailed at the break.
Warrington coach Tony Smith started with youngster Declan Patton at scrum-half, despite Chris Sandow - who was among the substitutes - begin passed fit.
Patton scored the only try of the opening period, dummying through from first-receiver on 21 minutes after Daryl Clark had darted out of acting-half.
Patton also converted and Jack Hughes lost the ball over the line trying to add a second try soon afterwards.
Wigan made several breaks with eventual man of the match Liam Farrell, Sam Powell and Dan Sarginson all being denied by outstanding scrambling defence on Warrington’s line.
Charnley got over, but Anthony Gelling’s pass was forward.
Warrington thought they had gone further ahead 13 minutes into the second half when Ryan Atkins crashed over, with defenders Gelling, Ben Flower, Smith, Charnley and Sarginson hanging on to him.
Referee Robert Hicks indicated a try, but video assistant Ben Thaler disagreed, spotting the former Bradford and Wakefield man had knocked on over the line.
Wigan surged upfield from the 20-metre restart, George Williams sent Farrell into space and Oliver Gildart was in support to slide over.
That was the 100th Grand Final try, the first being Richie Blackmore for Leeds - against Wigan - in 1998.
Smith could not convert’, leaving the scores locked with 24 minutes left, but Wigan struck again six later.
Former Hull winger Tom Lineham knocked-on playing the ball near his own line and following the scrum Sarginson dabbed a grubber over the whitewash and Charnley touched down.
Again the conversion was missed, but Smith opened a six-point gap with seven minutes remaining by booting a penalty goal after a ball steal by Clark on Sean O’Loughlin.
That looked a harsh decision. Warrington had a couple of late chances when Matty Russell was barged into touch by Charnley and Gelling, then Sarginson tackled Joe Westerman just short.
There was delight for Wigan’ ex-Wakefield forward Taulima Tautai and former Castleford man Willie Isa.
Ex-Leeds Rhinos man Ryan Bailey was on the losing team in his eighth Grand Final, alongside Atkins and former Cas duo Westerman and Clark.