Latics advanced to the FA Cup First Round thanks to a second-half goal from an unlikely candidate in Harrison McGahey.
Harrison came into the Latics line-up for the first time since Woking away, 396 days ago, starting in a defensive midfield role.
Neither side really managed to get a grip on the game, with it being end-to-end stuff at times.
Alty hit the bar through Angus and had a few shots saved, but the pivotal goal came from Tollitt’s corner.
Ben swung in his cross, the hosts failed to clear, and Harrison was there to poke it home from inside the 6-yard box.
Oldham defended well as Alty threw the kitchen sink at them, advancing to the 1st round for the 119th consecutive season.
Both sides attacked each other from the get go, the first of which saw Lundstram move into the box and look to get a shot away from a tight angle against his former side, but he was denied.
Chris Conn-Clarke beat his man and zipped the ball across the face of goal, but thankfully for Latics a red shirt wasn’t there.
Hudson was called into action when he had to deal with Alex Newby’s long-range effort, he could only palm it away to Dior Angus, whose shot was blocked by Hobson and follow up hit the side netting.
Angus had another chance moments later, he was seeking the far corner with a low curling shot, but Hudson was able to parry it away as it skid unpredictably on the muddy Moss Lane pitch.
Brennan Dickenson was forced off after half an hour when he collided with the advertising boards in front of the Latics fans, with Ben Tollitt replacing him.
The best chance of the first-half occurred just before the referee blew his whistle. Conn-Clarke received possession of the ball inside the box, and was unmarked, but he scuffed his shot, giving it to Newby, who was also unmarked. He had a clean shot on goal, but didn’t hit it with an accuracy, leaving Hudson worriless as it flew wide of the goal.
Moving into the second half, Latics really stepped up their game, and looked a lot more promising in attack.
Tollitt looked for the top far corner with a bending effort as he cut in from the left, but Ross in between the Alty sticks was able to palm it away.
Angus made a dire miss when he was one-on-one when he was played through, he just had Hudson to beat inside the box, but could only hit the woodwork before Latics cleared.
Oldham were dealt another injury blow when Devarn Green went down on his shoulder or back following an aerial challenge, he was replaced by Alex Reid who took up the role on the right wing.
And Reid had a golden chance to put Latics ahead, he had just the ‘keeper to beat with the ball bouncing before him, but didn’t make proper contact as he lobbed it over him, and Altrincham retook possession.
McGahey tried his hand at shooting when the ball fell promisingly to him just outside the area; the thunderous shot was destined for the top corner, but it was deflected just wide of the goal, setting up the sequence of corners which would spawn the goal.
Tollitt put the corner in, it fell within the region of the 6 yard box and Altrincham failed to clear, after a blocked shot or two, it came to McGahey who poked it over the line, scoring just his second goal for Latics, with his other also coming in the FA Cup, back in November 2021 against Ipswich.
Altrincham turned up the heat in the last 15 minutes or so, Latics defended bravely as balls were pumped in, denying them of any chance on goal.
Latics will find out their opponents in the First Round tomorrow on ITV at 14:30pm
Oldham: Hudson, Kitching, Hogan, Hobson, Lundstram, Sheron, Green (Reid, 71’), McGahey, Sutton, Dickenson (Tollitt, 30’), Norwood.
Subs not used: Norman, Shelton, Willoughby, Fondop, Raglan.
Attendance: 3,874 (1,115)