Anthony Gelling scored a hat-trick as Wigan reignited their campaign by whitewashing their fiercest rivals.
The win avenged a derby defeat at the DW less than a month earlier, and kept Saints at jabbing-distance away in the Super League ladder.
Wigan were not at their best for large spells, but perhaps it would be greedy to want a derby win and a flawless display!
This game frequently stalled, with both sides turning over possession, but the home side improved in the final quarter and were certainly good value for the two points.
Gelling’s two tries in the first-half, both converted by Matty Smith, had put them into a 12-0 lead by the break.
By the final 15 minutes, they had only managed to add one more point to their score - courtesy of a Smith drop-goal.
But they finished strongly, Gelling completing a memorable night by plucking Jordan Turner’s pass out of the air and storming 90m down field to seal his hat-trick.
George Williams provided the crowning glory by sliding over under the sticks, with Smith’s goal taking them to a 25-0 - within touching distance of their famous 27-0 scoreline at Wembley in 1989.
Williams was again impressive, and while Gelling was an obvious choice as man of the match, prop Taulima Tautai and forward Liam Farrell also made notable contributions.
This win was significant.
It was only their second win in six matches, and it halted Saints’ seven-game winning streak.
More crucially, it wedged a four-point buffer between the rivals - in third and fourth position in the ladder - with four games of the Super-8s to go.
And it sent them into the extended break, for the Challenge Cup Final, in a buoyant mood which a comfortable win against Saints, and keeping them to ‘nil’, will provide.
The top-four go into the play-offs, but this victory kept Wigan’s hopes alive of a top-two finish - and a home semi-final at the end of September.
Williams and Josh Charnley recovered from knocks to take their place in the side, while Wane gave Oliver Gildart first chance to fill the wing spot vacated by Dom Manfredi’s serious knee injury.
In the scramble for prop places, Lee Mossop missed out.
Saints were rocked by the suspension of halfback Luke Walsh, which earned Frenchman Theo Fages a recall after two months out.
Wigan edged the opening half 12-0 but the opening 40 minutes had far more spills than thrills.
After an intense start, Gelling scored the first of his two tries when, gripping the ball in one hand, he rolled over to cross before sweeping into touch.
Smith nailed the sideline conversion, to a backdrop of a few pantomime boos - he is expected to leave Wigan for St Helens at the end of the season.
From that point, though, Saints turned the table and had the better position on the pitch and more possession - without having to work particularly hard for it.
The Warriors had a string of repeat-sets to defend, and on top of that, they proved their own worst enemy by repeatedly spilling the ball inside their own half.
Their defensive effort was much more accomplished; they defused Saints’ best chance by bundling Adam Swift into touch.
The introduction of Frank-Paul Nuuasala and Tautai added more punch down the middle, and one brief venture into Saints territory saw Dan Sarginson show his balance and class to cross the line, only for a try to be ruled out for a forward pass.
Still, it was an encouraging sign, and on the half-hour mark Gelling punished a stretched defence for his second try - his forefinger-to-the-lips ‘hush’ sign to the Saints fans will only swell his popularity among the Warriors faithful. Smith’s second goal made it 12-0.
But again, Wigan handed Saints opportunities to reply, first when Gildart failed to deal with a regulation kick, then when Gelling turned over possession with an unnecessary pass.
Wane’s instructions at half-time must surely have been to control the ball better, and they did that for a spell.
With neither side showing capable of mounting a serious, and sustained, attack, Smith opted to slot a drop-goal before the hour-mark to put them into a three-score lead.
And while the passages showed little sign of improving, the ticking clock made it strangely entertaining.
Gelling went over from long-range to seal his hat-trick and, at 17-0, their focus switched to keeping their opponents to nil by the siren, which they did - but not before Smith had extended their lead with a penalty and Williams had swept over for a try.
Wigan: S Tomkins; Charnley, Gelling, Sarginson, Gildart; Williams, Smith; Crosby, Powell, Flower, Bateman, Farrell, Isa. Subs: Tautai, Sutton, Nuuausala, Shorrocks.
St Helens: Lomax; Owens, Fleming, Peyroux, Swift; Turner, Fages; Walmsley, Roby, Richards, Greenwood, Knowles, Wilkin. Subs: Amor, Vea, McCarthy-Scarsbrook, Tasi.
Referee: Ben Thaler
Starman: Anthony Gelling