Their last victory in any competition was six years ago, but they repeated the dose in the most astonishing fashion yesterday in the Stones Centenary Championship, winning 28-26 in the last couple of minutes despite fielding a team badly weakened by injury.
Oldham got off to the worst possible start, trailing 12-0 to two early Wigan tries. But the Tongan wing Afi Leuila matched his lifelong friend, Va'aiga Tuigamala's two tries in the first half to pull them back to 20- 12.
Wigan seemed to have ensured victory with Martin Offiah's second try of the match four minutes from time. But a try from the former Wigan scrum-half, Martin Crompton, tied it up and Francis Maloney kicked the conversion for the most unlikely of victories.
It was a triumph for two other Wigan luminaries, their former full-back, Paul Atcheson, who won the man of the match award for a series of try-saving tackles, and the ex-Central Park favourite, Andy Goodway, who is now Oldham's coach.
"I told my players not to be frightened of Wigan's reputation," said Goodway of a side that had won only three league games all season.
"We froze a bit early on, but once we started to play we showed what we can do."
The Wigan coach, Graeme West, had no excuses for his side's second loss of the season. "Oldham came back at us and we didn't help ourselves by spilling a couple of bombs, one of which led directly to their winner," he said.
It is still a cast-iron certainty that Wigan will win the championship, but their unexpected embarrassment at the Watersheddings yesterday at least enabled Leeds to make some inroads into their commanding lead.
Leeds had their first win in four championship matches, beating Bradford Bulls 16-12 in an injury-strewn game at Odsal. Both sides finished with 12 men after running out of substitutes and Bradford's new signing, Sonny Nickle, was taken to hospital with a whiplash injury to his neck.
Neil Harmon was Leeds match-winner with two tries, but Paul Cook had an unhappy debut for Bradford against his former club which he left last week, kicking just two goals from six attempts.
Grant Anderson scored his first tries for Halifax in their 26-12 win over Workington, while Salford opened a three-point gap at the top of the first division by beating Rochdale 42-4. Their centre Scott Naylor grabbed two tries and created another as the Reds stretched their unbeaten league run to nine games.
The biggest shock came at third-placed Widnes, who lost 18-14 to Huddersfield. After leading 10-0 the visitors scored three late tries - two from Greg Austin - despite having prop Andy Pucill sent off seven minutes from time for a high tackle on Paul Hulme.Reuse content