First half goals from Malone and Martin gave the Reds too big a hurdle to climb and although Jamie Paterson struck on 53 minutes there was to be no comeback and no big reaction to the midweek news that Stuart Pearce will return to the club in the summer.
Forest are now five points adrift of the play-off places while Millwall manager Ian Holloway was left to reflect on a crucial win in their fight against relegation.
"The crowd got behind them in the second half and we hardly got a decision out of the referee," he said. "But we got the win."