Chesterfield boss Dave Rushbury threatened to quit after watching his side fall apart at Boundary Park.
Rushbury will seek showdown talks with his chairman as the Spireites plunged deeper and deeper into relegation trouble.
They have won only two games out of 18 and were totally outclassed by Oldham, who gave their automatic promotion push a massive boost.
Rushbury said: "I will speak to the Chairman about my position - I am seriously considering resignation.
"I don't want to leave anyone in the lurch but I am not sure I can put myself through much more of this.
"I've had some marvellous times during 15 years at the club and now I am not sure what the future holds.
"There is potential here so maybe it's time somebody else tried to bring it out because that job is possibly beyond me.
"In the last few months we have been fighting against all sorts of things and the players' heads have begun to drop.
"They are a great bunch of lads and I hope they stay up but we look like a team heading into Division Three." Oldham had already missed chances when Wayne Andrews headed them in front on 19 minutes.
The striker rose at the far post to convert a Paul Murray cross for his 11th goal of the season.
Chesterfield were to blame for the second, seven minutes later as Clyde Wijnhard pounced on a defensive blunder to slot home from eight yards out.
The visitors rallied briefly and ex-Oldham man Mark Allott hit the post from distance but they were always under pressure before the points were secured with 15 minutes left.
A centre from Josh Low gave Wijnhard the chance to double his tally from close range, before Latics' leading scorer David Eyres drilled in his 14th of the season from a tight angle.
Oldham manager Iain Dowie said: "Some of our football was tremendous and we will go to Wigan on Monday for a massive game with great confidence."