Player-manager Mark Cooper and substitute Peter Folkes were both dismissed by referee Tony Taylor as Tamworth, rooted in the relegation zone, fought for their Conference lives.
Play-off hopefuls Exeter arrived at The Lamb in relegation form themselves. They had lost their last three away games and had picked up just three points from the last seven games.
However, they took the lead after just 50 seconds as Lee Phillips wriggled to the by-line and crossed for Jon Challinor to score at the far post.
But with Cooper deciding to lead from the front after having a pain killing injection to sooth a shoulder injury, the Lambs fought back and equalised in the 18th minute when Scott Stamps' deep cross was met at the far post by the Lambs boss.
Sean Bowles made a superb save, the first of many, to deny Challinor again after 25 minutes but Tamworth also should have scored as Dave Bampton headed a corner back into the six-yard box only for Matt Redmile's close-range shot to be blocked on the line.
In first-half injury time, Cooper received a second booking for a mis-timed tackle on Challinor and the Grecians looked favourites to go on to win the game.
Bowles denied Paul Buckle and Billy Jones with some tremendous saves and the post came to Tamworth's aid on two occasions.
Five minutes were added on and tempers frayed as Folkes was dismissed for a shove on Flack and in the ninth minute of added time, Challinor thought he had scored the winner but the flag cut short his celebrations.