Burnley's Jay Rodriguez headed a goal in each half to send Nottingham Forest to a sixth straight defeat.
Rodriguez opened the scoring with a close-range header from Kieran Trippier's cross after three minutes.
Having missed a penalty, awarded for Garath McCleary's foul on Ben Mee, Rodriguez then headed his second from another Trippier cross.
On-loan Wolves man Adlene Guedioura went closest for the hosts but fired straight at Burnley keeper Lee Camp.
Rodriguez, given his first professional contract by Forest boss Steve Cotterill when he was in charge at Burnley, has now managed 16 goals in all competitions, while Forest - 23rd in the table - have not scored at the City Ground since 19 November.
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Nottingham Forest boss Steve Cotterill told BBC Radio Nottingham:
"It's difficult times at the moment, very difficult times. It's very difficult when you have to have a makeshift back four, and to get off to that sort of start makes it an uphill battle.
"Jay Rodriguez is a young boy who I know very, very well, and he is very, very good in the box.
"Now we've got a couple of loan signings we can bring in. One's a good young player and Danny Higginbotham will come in with good experience and good leadership skills. So the team's going to change around again.
"We needed this two months ago but we didn't have the money. That's what's made it a prolonged and painful time."