Andrew Omobamidele scored an own goal to gift Brighton victory and dent Nottingham Forest’s chances of Premier League survival.
The Forest defender turned Pascal Gross’ curling free-kick into his own goal in the 29th minute.
Nuno Espirito Santo’s side pushed in search of an equaliser after the break but a lack of quality in the final third meant they failed to salvage a crucial point.
The defeat leaves them just three points above 18th-placed Luton in the relegation zone, although the Hatters have a game in hand.
Returning from a 4-0 thumping by Roma in the Europa League on Thursday, Brighton dominated both possession and chances in the first half.
Jakub Moder’s glancing header called Forest keeper Matz Sels into action, while Evan Ferguson came close to netting his first goal since November’s meeting with the same opponents, but he couldn’t squeeze in at the near post.
The Seagulls kept pushing forward and were eventually rewarded when Irishman Omobamidele, who was lucky to avoid a second yellow card for fouling Ansu Fati on the edge of the box, nodded the resulting free-kick into his own net.
Forest should have levelled straight away but Divock Origi couldn’t fire past Bart Verbruggen when one-on-one with the Brighton goalkeeper.