Wellens ran in four tries for the second time this season
St Helens: (22) 34
Tries: Meli, Wellens (4), Gidley
Goals: Sculthorpe (5)
Wigan: (6) 18
Paul Wellens ran in four tries as St Helens held off Wigan to return to the top of the Super League table.
Tries: Fletcher, Ashton, Goulding
Goals: Richards (3)
Francis Meli struck first for Saints and although Bryan Fletcher replied for Wigan, Wellens and Matt Gidley touched down to give Saints a 10-point lead.
Wellens showed good dribbling skills to go over again and his third and fourth came either side of Chris Ashton's try.
Darrell Goulding kept Wigan in the game and Trent Barrett wasted a great chance as he dropped the ball over the line.
The champions drew first blood when Meli capitalised on Jon Wilkin blocking a kick, and although Fletcher soon levelled from Thomas Leuluai's pass, Wigan were not on equal terms for long.
When Trent Barrett was drawn out of the defensive line it created a gap, which Wellens raced through, side-stepping Chris Ashton to score.
Gidley danced over after Willie Talau burst through but was hauled down inches short of the line by Barrett.
Sean Long, Leon Pryce and Bryn Hargreaves worked the ball out to Gidley on the right and he touched it down.
Wellens' footballing skills earned him his second try, despite queries about whether or not he touched the ball down properly.
Wigan were left reeling by this early barrage but as the half wore on they got more into the game, and Micky Higham can count himself unlucky to have lost his footing when bearing down on goal.
Considering Saints half-time lead, the first score of the second half was always going to be vital, and it went to the men in white, as Wellens dummied to go over in the right-hand corner.
Ashton's persistence, strength and quick thinking earned him a try after a chip and chase to give Wigan a foothold in the game.
But the way Saints replied was spectacular, shunning the chance of a two-pointer - to the clear irritation of coach Daniel Anderson - instead scoring six, as Wellens scored a converted fourth.
When Goulding scored after a burst by Barrett, Wigan realised they could still win it and after four successive sets of six, they had a great chance but Barrett lost control as he went to ground the ball.
St Helens coach Daniel Anderson on Paul Wellens:
"He was absolutely superb and once again was fantastic at finishing but he is the first to admit he can't win games by himself.
"A lot of blokes made significant contributions. Francis Meli is on fire at the moment.
"I thought the officiating was inconsistent. Every dud call went against us so to win with that style was tremendous."
Wigan coach Brian Noble:
"The game went away from us starting in the first half. We keep opening the door and slamming it shut in our face.
"Our kicking game was poor in the first half. We improved in the second half and stood up a little bit but we weren't patient enough.
"We made enough breaks to score another 18 or 24 points but we didn't and we couldn't defend our own line well enough.
"I'm really frustrated. There is a good team in there waiting to get out. The effort is there, which is a good thing."
St Helens:Wellens, Tyrer, Gidley, Talau, Meli, Pryce, Long, Fozzard, Cunningham, Cayless, Wilkin, Sculthorpe, Hargreaves. Replacements: Roby, Graham, Clough, Fa'asavalu.
Wigan: Ashton, Calderwood, Bailey, Vaealiki, Richards, Barrett, Leuluai, Fielden, Millard, Paleaaesina, Hock, Fletcher, O'Loughlin. Replacements: Higham, Prescott, Hansen, Goulding.