In their first home match since losing 3-0 to local rivals Leeds, Rovers fell behind against the run of play as Sammy Clingan smashed in a first-half opener.
But the hosts, without influential frontman Billy Sharp, enjoyed plenty of possession and were grateful to Hayter, who equalised on the hour mark.
Both sides pushed hard for a vital winner, but Coventry, who slip into the relegation zone, are still without an away league victory this season while second-bottom Rovers have not won in four matches.
Striker Hayter saw a shot blocked by Nathan Cameron as the hosts started the brightest.
Rovers continued their early dominance and almost opened the scoring through Kyle Bennett, but the striker's header was straight at Joe Murphy.
Giles Barnes glanced a header wide from Brian Stock's corner, but it was Coventry who surprisingly opened the scoring after 31 minutes. Clingan took advantage of some poor defending to smash in the opener from 20 yards.
Carl Baker almost doubled the Sky Blues' advantage, with veteran goalkeeper Neil Sullivan, fresh from signing a new deal at the Keepmoat Stadium this week, having to tip over the midfielder's 12-yard effort.
Doncaster started the second half as threatening as they did the first and Bennett tried his luck, only to see his shot from distance fly over the bar.
Rovers, after some neat passing, had another chance through the lively Bennett, but once again his missed the target, this time trying his luck from 18 yards.
However, the hosts did find a leveller through Hayter, who converted from 12 yards following smart work from James Coppinger.
Coventry almost caught the rampant Rovers off guard, with full-back Cyrus Christie firing a viscous 20-yard strike just wide.
The visitors continued to catch Rovers out and leading-scorer Lukas Jutkiewicz almost got the second, only to see his effort fizz across the face of the goal.
Five-goal forward Jutkiewicz, taking advantage of a mix-up in the home defence, wasted a great opportunity to give his side the lead but, when 14 yards out, the striker shot straight at the sprawling Sullivan.
The Sky Blues started to dominate, this time Cody McDonald threatened to net after 80 minutes, with Sullivan parrying to the ball to Jutkiewicz, who failed to convert the rebound.
Midfielder Simon Gillett almost won the game for the home side with a 20-yard free kick Murphy had to tip over.
Coppinger threatened to create a winner for the hosts but the points were shared.