Saints clinch top spot
Saints ended a run of 10 successive defeats at the JJB Stadium with one of their most important wins in a ferocious, ill-tempered derby in front of a 20,274 crowd to pull five points clear of Leeds, who have two matches left of the regular season.
But victory came at a price with acting captain Sean Long and leading tryscorer Darren Albert taken to hospital with suspected broken cheekbones and Lee Gilmour also going off with a head injury before half-time.
As well as running out of players, Saints had two men sin-binned but they were still too skilful and powerful for a brave but outclassed home side.
Depleted Wigan, who gave a debut to 18-year-old forward Lee Jewitt, went into the game hoping for a fifth straight win but this was clearly a game too far.
London Broncos? 26-18 defeat at Salford kept alive their slender play-off hopes but they looked a tired side after being outplayed by the new title favourites, who had the last laugh on their former coach Ian Millward.
The Warriors enjoyed most of the early possession but Saints struck first after dangerous Australian centre Jamie Lyon skilfully carved out an opening for Albert. A terrific cover tackle from Joel Tomkins halted the move but a quick play-the-ball got Keiron Cunningham charging through a gap to score.
Wigan were quickly level thanks to a superbly-crafted try by centre David Vaealiki in which the ball was smartly passed through several pairs of hands but they spent most of the rest of the half on the back foot.
St Helens full-back Paul Wellens jinked his way over for a solo try on 17 minutes and Long kicked his side into a 14-6 lead after their hosts conceded a series of penalties.
As Wigan?s discipline began to let them down, hooker Terry Newton was placed on report on 22 minutes for a high tackle that left Saints second rower Gilmour poleaxed.
Gilmour, carried off on a stretcher, had been acting as a makeshift winger following the early loss of Albert but Saints shrugged off the further disruption to strengthen their grip on the game.
The visitors even managed to shrug off the absence of star man Lyon, sin-binned on 30 minutes for a professional foul, to score two further tries while down to 12 men.
Magnificent running and handling by centre Willie Talau set up a easy score for winger Ade Gardner and Cunningham forced his way over from dummy half in trademark fashion for his second try of the half.
With Long forced off with the facial injury, the result of a collision with team-mate Maurie Fa?asavalu, Jason Hooper took over the goalkicking and his conversion of Saints? fourth try made it 24-6.
Wigan grabbed themselves a lifeline just before the interval when Vaealiki gathered Danny Orr?s grubber kick and combined with Martin Aspinwall to get Tomkins over for a deserved score, with Danny Tickle kicking a second conversion from the touchline.
There was no let-up to the fast and furious action in the second half, nor little sign of tempers mellowing.
Lyon, fresh his spell in the ?cooler?, extended his side?s lead with a penalty early in the second half and St Helens put the game beyond their rivals? reach on 52 minutes when Cunningham combined with Hooper to send substitute Jon Wilkin over for a fifth try.
Wilkin blotted his copybook five minutes later when he was shown the yellow card for diving into a melee but Saints finished in control and, after prop Paul Anderson had a score disallowed by video referee Steve Presley, they scored a sixth try through substitute Fa?asavalu, with Lyon kicking his third goal.
Wigan: Dallas, Carney, Brown, Vaealiki, Aspinwall, Orr, Moran, Allen, Newton, Guisset, Wild, Tomkins, Tickle. Replacements: Hansen, Sculthorpe, Beswick, Jewitt.
St Helens: Wellens, Albert, Lyon, Talau, Gardner, Hooper, Long, Fozzard, Cunningham, P. Anderson, Gilmour, Bennett, Roby.
Replacements: Higham, Graham, Fa?asavalu, Wilkin.
Wigan (12) 12. Tries: Vaealiki, Tomkins. Goals: Tickle 2.
St Helens (24) 38. Tries: Cunningham 2, Wellens, Gardner, Wilkin, Fa?asavalu. Goals: Long 3, Hooper, Lyon 3.
Referee: Ian Smith (Rotherham)