Oldham turned the League One form book on its head by making light work of leaders Scunthorpe in a 2-0 victory.
The struggling Latics had failed to win any of their six previous league matches at Sportsdirect.com Park, but doubled their goal tally for the season in front of their own fans on their way to a comfortable three points.
Two goals in the three minutes directly before half-time did the damage for Oldham.
Freddie Ladapo grabbed the first, in the 42nd minute, completing a flowing move upfield by squeezing a shot inside the upright.
The Iron were still reeling from that setback when Lee Erwin broke into the box and curled a lovely finish inside the far post a minute into stoppage time.
Scunthorpe, unbeaten in eight games going into the clash, never looked like finding a way back into the game and lacked ideas in the final third.
Instead it was Oldham who went closest to adding to the scoring after the break when visiting goalkeeper Joe Anyon did well to beat away a drive from Ryan Flynn.