Another tight game involving the Reds was settled in favour of Dougie Freedman's side when Oliveira struck in the 37th minute.
A vital three point-haul ends Forest's run of defeats and moves them onto 45 points, 10 clear of Rotherham United who caused the shock of the evening by beating Middlesbrough at the New York Stadium.
16,747 watched the action at the City Ground with a bigger crowd set for Saturday's home clash with Sheffield Wednesday.
More to come on Forest Mad.