A Matt Mills header from a stoppage time corner was pushed onto the post by Blackburn goalkeeper Jason Steele in the final meaningful action of a hard-fought game.
Rovers had the better of the first-half before the second 45 minutes became gradually more scrappy.
Dougie Freedman shuffled his pack having seen his side in action on Friday evening at Wolves and will be content to have come away from two tough fixture on the road with two points to add to the six taken from home games against Reading and Fulham.
The Reds stay 15th in the Championship ahead of Tuesday night's fixtures and they now they have an extra day to prepare for Saturday's City Ground clash with an MK Dons side currently in the relegation zone in the Championship.
Match Reaction: Home boss Paul Lambert felt his side 'dominated' the game and that the opening 45 minutes was 'the best since I've been here.'
Dougie Freedman did not disagree that Forest had been under pressure in the first half but commented: "I thought we coped very well against a physical, direct Blackburn side."