Leeds missed the chance to return to the top of the engage Super League after going down to a revitalised Wigan in an error-strewn encounter at the JJB Stadium.
The Warriors produced a Herculean defensive effort to keep their tryline intact and mastered difficult conditions to successfully follow up their surprise win over Bradford with a fourth successive victory over the Rhinos.
The four points gained over the last eight days will be crucial if, as expected, Wigan are docked points when they face a charge of breaching the salary cap.
That will be the last thing on the mind of coach Brian Noble after his side outplayed the Yorkshiremen to gain their third win of the season over them.
Noble sprung a surprise by switching the returning Pat Richards to full-back in place of rugby union-bound Chris Ashton, with Liam Colbon keeping his place on the wing, but move paid off, with the pair contributing all but four of Wigan's points.
The Warriors put themselves under early pressure, with Trent Barrett kicking out on the full and Bryan Fletcher knocking on in front of his own posts, and it almost proved costly when Leeds full-back Brent Webb jinked his way through a gap in the home defence.
The chance came to nothing when Webb lost his footing on the slippery surface, the first of a series of errors in the difficult conditions.
Webb then put his side in trouble when he dropped Barrett's high kick and the Rhinos were relieved when centre Wigan centre Phil Bailey reached the line only to be turned on his back by winger Scott Donald.
Wigan eventually opened the scoring through the boot of Richards after prop Ryan Bailey was pulled up for a high tackle on Iafeta Paleasesina and the Australian kicked a second penalty when Webb was punished for interference in the tackle.
The handling errors continued apace in the second half, with Thomas Leuluai, one of Wigan's better players in the first half, and Leeds second-rower Jamie Jones-Buchanan both coming up with fumbles.
There was a moment of real alarm in the Leeds defence when Donald spilled the ball in his own in-goal area and Wigan looked to have scored from the resultant drop-out.
Colbon took centre David Vaelaliki's neat pass to cross at the corner but slow-motion replays showed he put a foot on the touchline and video referee Steve Ganson disallowed the try.
Wigan did gain some reward when Richards slotted over a third penalty on 49 minutes to make it 6-0 but Leeds reduced the arrears when skipper Kevin Sinfield, playing out of position at hooker, put over a penalty after Fletcher had been pulled up for an incorrect play-the-ball.
The Leeds line was under almost constant siege and the pressure finally paid off courtesy of another blunder from Webb, who failed to clear the danger posed by Leuluai's grubber kick.
Colbon managed to get his hand on the ball before it rolled dead and Ganson this time gave the young winger the green light.
Fletcher then piled on the agony for the visitors when he crashed over for a second try nine minutes from the end and Richards maintained his 100% record by landing his fifth goal.
Leeds' misery was complete a minute from the end when loose forward Gareth Ellis was sin-binned for dissent.