Kenny Miller struck promotion-chasing Cardiff City's winner as the Bluebirds plunged Nottingham Forest deeper into Championship relegation zone trouble.
Peter Whittingham underlined the reasons for West Ham United's recent interest by whipping in a cross for Miller to head into the top corner.
Defeat left Forest without a win in seven games as they failed to test visiting goalkeeper David Marshall.
Miller missed two chances before his 59th-minute winner.
But the hosts' goal drought was extended to a club record seven games as the Bluebirds secured a first league win in four matches.
Forest's Paul Anderson failed to recover after hurting his hamstring in the home defeat by Peterborough on Boxing Day.
But defender Joel Lynch banished doubts about his fitness while Cardiff defender Kevin McNaughton could not overcome a calf problem.
The hosts dominated the goal-less opening period in which the visitors' only good chance fell to Millar.
But goalkeeper Lee Camp was equal to the challenge to deny the visitors.
Forest unsettled the Bluebirds at the start of both halves, Marshall earning a booking in the opening minute as he rushed into a challenge on Robbie Findlay.
Within five minutes Findlay had departed with a shoulder injury to be replaced by Matt Derbyshire.
Despite an encouraging start and enjoying the greater share of possession, Forest could not break down a resolute visiting defence.
Miller's goal came against the run of play, although the Bluebirds looked more dangerous in front of goal throughout.
McGugan was Forest's most dangerous player and their best chance fell to him as Forest sought an equaliser.
But the highly-rated midfielder's 30-yard volley beat Marshall, only to scream past the post.
Rudy Gestede, one of the visitors' best performers, had a chance to stretch the Bluebirds' lead late on, but his header also went wide.