Substitute Matt Smith stepped off the bench to score the match-winning goal at Bury as Latics took a giant step towards npower League One safety.
Only 11 minutes were left when Smith made the breakthrough as Latics left Gigg Lane with three valuable points on the day bottom-club Bury's relegation was sealed.
You only had to look at the size of Latics’ following – 2,073 with an estimated 300 locked out – to see the importance of the fixture.
And while the match, which was played in driving rain, was no classic, Latics produced a battling display to earn victory.
Manager Lee Johnson was delighted declaring: "It was a heroic display of mentality because it was not a great first half and in the second we had to make sure we were more positive and didn’t concede.
"Afterwards I told the players I was proud of them for winning a tough, tough game."
Johnson admitted Latics' first-half display wasn’t the best but thought they were the superior side in the second.
He said: "In the second half we had them on the rack and the substitutes made a difference. In the end it was a very good win and good away performance.
"We had to win the battle and it must have been an emotional day for supporters. It was going to be intense and we had to play the right characters for the day."
Johnson also praised the fans saying it was better than a home match with over 2,000 fans packed together behind the goal singing their hearts out.
He said: "It was as though they were almost sucking it into the goal and you saw how passionate everybody was. The fans also saw how passionate the players were at the end and also when we scored.
"The atmosphere made the hairs stand up on the back of my neck and, if it did that to me, I am sure it also did so to the players."
Latics made four changes from the midweek defeat at Preston, three of which were enforced.
Jose Baxter was ruled out through suspension while James Wesolowski and Cliff Byrne were injured.
"Sometimes when you lose key players like that, it feels as though you could be going under. I still had faith that the players coming in were good enough," he explained.
Johnson has a new central midfield pairing of Korey Smith, who played right back at Preston, and David Mellor.
Connor Brown and James Tarkowski returned to the back line and Cristian Montano to the left wing as he made his first start since New Year’s Day.
It was an opening half when there was precious little goalmouth action as the importance of the match and pressure clearly affected both sets of players.
Montano forced an easy diving save from home keeper Cameron Belford while Latics’ stopper Dean Bouzanis had to beat out a shot from Nicky Ajose after the winger cut in from the left.
Andy Bishop saw a head flash just wide while late in the half Lee Croft and Robbie Simpson, captain for the day in the absence of Wesolowski, also had efforts off target.
It remained cagey in the second period, though Latics began to exert more control. Still, however, there were precious few scoring chances.
Brown made a great run to set up Lee Barnard who shot over and wide while a drive from Bury’s Zac Thompson flew just wide.
The turning point and pivotal moment in the match came midway through the second half when Johnson made a double substitution replacing Barnard and Simpson with Matt Smith and Kirk Millar.
And it was that pair who combined 15 minutes later for the match-winning goal as Millar delivered a delightful hanging cross from the left which was food and drink for the 6ft 6in who dived in to head home from no more than four yards out. It was his ninth goal of a memorable campaign.
The sigh of relief, both on and off the field was palpable as everybody was acutely aware of how important a goal it was and ultimately could be for Latics in this campaign.
Latics could conceivably have scored again in the third minute of stoppage time – five were added and almost seven played – when Mellor fired over a fine free kick from near the corner flag and Smith's far-post header was desperately clawed out by Belford.
And at the final whistle, the scenes of celebration underlined just how important a win it might be. Had Latics won a cup final or secured promotion, it would have been hard to surpass the scenes of unbridled joy.
Bury (4-4-2): Belford; Worrall, Eastham, Hughes, Ebanks-Landell (Mezague 46); Soares, Carrington, Thompson, Ajose; Bishop (Pratt 88), Clarke-Harris (Healy 69). Sub (not used): Regan.
Latics (4-4-2): Bouzanis; Brown, Tarkowski, M’voto, Grounds; Croft, K Smith, Mellor, Montano (Reid 90+2); Simpson (Mellor 64), Barnard (M Smith 64). Subs (not used): Iwelumo, Jacob, Winchester, Belezika.
The goal: M Smith (79) for Latics.
Bookings: Eastham (55) for Bury, Brown (10), M’voto (31) for Latics.
Referee: Mr P Gibbs (West Midlands).
Attendance: 4,558 (2,073 visitors).