The visitors took the lead after just eight minutes of the game at Damson Park through Julian Bennett but James McPike equalised for Keith Bertschins side 18 minutes into the second half.
However, just under ten minutes after Blues equaliser Forest sealed victory through Jon Pittman.
One major plus from the game was that centre-back Matthew Upson completed an hour in this his first competitive action since picking up an Achilles injury during the pre-match warm up at Villa Park in April.
Blues: Doyle, Howell, Painter, Oji, Upson, Hall, Birley, Kilkenny, McPike, Allen, Price.