A rare Wes Morgan strike gave Nottingham Forest the lead before former transfer target Peter Whittingham's penalty hauled the Welshmen level.
It was one of Cardiff's former heroes however who downed his old club, Robert Earnshaw striking a superb winner to push Billy Davies's men into second place in the Championship.
26,019 watched a great game at the City Ground and the majority will leave with Premier League dreams firmly intact.
Reaction to follow on Forest Mad.