Oldham Athletic 2 Doncaster Rovers 2
Hayter, a big-money signing from Bournemouth, struck twice in the last half-hour to cancel out goals from Neal Trotman and Craig Davies.
Oldham were torn apart by injury but their young side performed well as they tried to build on a recent improvement in league form.
Doncaster however had the heart for a battle and stretched their unbeaten run to eight games in all competitions.
The visitors almost went in front within the first five minutes as the ball rebounded to Martin Woods and his effort was bundled to safety off the foot of the post.
But Oldham got their passing game together and almost made the breakthrough when Davies got his out-stretched leg to a pass from Neil Kilkenny and saw it hacked off the goal-line by Gordon Greer.
Hayter missed an opening for Doncaster midway through the first half, but Trotman gave Oldham the lead with his first goal of the season.
The big central defender jumped highest from a Kilkenny corner and thumped his header into the net from ten yards.
The lead was doubled shortly after half-time when makeshift left-back Chris Taylor freed Davies for a run down the left.
Oldham's top-scorer lifted his tally to eight for the season when he cut inside and fired into the bottom corner from ten yards.
Doncaster's comeback began when Hayter took possession just inside the penalty area and beat goalkeeper Mark Crossley, who was struggling with a back problem, with a rising drive.
Rovers sensed their opportunity and it was 2-2 when former Oldham midfielder Richie Wellens did well inside the box and played in Hayter for another unstoppable drive, this time from ten yards.