It didn't start well for the Reds as Craig Westcarr limped off after half-an-hour from a 'last-man' challenge that the referee deemed to be fair.
Coventry managed to take the lead in the second half. Claus Jorgensen scored a diving header from six yards to beat Forest 'keeper Barry Roche after a curling cross from Dean Gordon on 65 minutes.
Former Arsenal youngster Graham Barrett nearly make it two halfway through the second half when his free-kick struck the top of Roche's crossbar.
Just when the game looked like a lost cause, Forest scored a dramatic last minute equaliser. Wes Morgan rose at the far post to head in from James Beaumont's corner to end the reserves' five-match losing streak.