"We were on the back foot for too long but we showed a lot of character to hang in there and protect the lead we had earned."
Forest have the chance to move into the top six this week when they entertain another of the division's form sides, Barnsley.
Newcastle manager Chris Hughton meanwhile, admitted the game at the City Ground was lost in the opening 45 minutes.
"We paid the price for a poor first-half performance when they were much better than us," he said.
Forest are now as short as 7/2 to end the season back in the top-flight of English football.