Nottingham Forest's recent run of five games unbeaten in all competitions was ended by Brighton as the Seagulls claimed a 2-0 win at the City Ground.
Since Sean Dyche's arrival at the end of October, Forest had lost just once and won each of their previous three matches prior to Sunday's game by three goals.
Brighton dominated the opening 20 minutes but failed to register any of their shots on target, before Forest began to find their feet.
It had been a good spell for the hosts when Brighton made the breakthrough on the stroke of half-time. Maxim De Cuyper was found unmarked in the box by Georginio Rutter, and swept home from close range.
Forest spent much of the second half trying to find an equaliser - racking up 11 shots to Brighton's four - but were undone by some poor defending from Morato.
He attempted to play a ball backwards under pressure inside his own box, only for Brajan Gruda to latch onto it and attempt to round Sels. The 'keeper nearly did enough but the ball fell kindly to 19-year-old Stefanos Tzimas to poke home.
Sels had earlier made a vital double save to keep out Diego Gomez and Ferdi Kadioglu, before Bart Verbruggen denied Igor Jesus at the other end. It was Sels who began the attack too, but Forest were unable to find the cutting edge that had served them so well in recent matches.
Brighton move up into fifth with the victory, and will go some way to exorcising the demons from last season's 7-0 defeat at the City Ground. Forest remain in 16th, just a point above the relegation places.
SportNews' Declan Olley:
Last season, Brighton were humiliated at Nottingham Forest after they lost 7-0 at the City Ground in February.
Nearly 10 months on, the Seagulls got revenge for that embarrassment with a brilliant win that shows they are serious contenders for a European spot this season.
Key to the victory was Maxim De Cuyper - a player who did not experience that thrashing in the East Midlands last season - as Brighton boss Fabian Hurzeler deployed the summer signing to great effect in a new position on the left wing.
From there, the Belgium international raided up the left and helped Brighton attempt nine shots in the opening 20 minutes of the match - their most ever in that period of a Premier League match.
And it was De Cuyper who deservedly made the breakthrough to cap off a fine first-half display. The 24-year-old was then awarded the man of the match as he created the most chances (4) and attempted the most crosses (4) of any Seagulls player.
Speaking to SportNews afterwards about his positional change, he said: "When I was younger, I played there a lot, so it was a bit weird in the beginning to play there again, but I'm happy there."
Meanwhile, much has changed at Forest since that 7-0 victory over Brighton, with a new manager, European football and a potential relegation scrap on their hands. But one of the key differences 10 months on was the absence of Murillo.
The Forest defender missed Sunday's game through injury, and his unavailability was keenly felt.
His replacement, Morato, had a shaky game that culminated in a mistake for Brighton's second.
Forest boss Sean Dyche, therefore, will be hoping Murillo's injury clears up ahead of a crunch relegation six-pointer at bottom-side winless Wolves on Wednesday, live on SportNews.
Nottingham Forest head coach Sean Dyche to SportNews: "It's a strange one with the performance after the first 20 minutes because that [start] was really poor. It felt like we were waiting for everyone else to do something but they [Brighton] certainly weren't waiting.
"Then we took a grip of the game and played very well for the second half of the first half.
"We gave away a soft goal and we should manage the game at that point. It's minutes on the clock and you just see that through, it's the basics.
"In the second half, I thought we were dominant. It's a mistake of a goal at the end, but we got in so many good areas.
"Weirdly, there a lot of good signs in our performance but you've got to score goals, which we have been doing to be fair.
"It's hard to question the players after that second half. It's a great reaction to being 1-0 down. There's no licking your wounds, we just got on with it straight away and that's got to be important to us.
"There are a lot of good signs here but we've got to turn those signs into wins, which we have done. Today is the one that got away from us, but not through lack of effort, just through lack of tactical disciple in the early part.
"Then for the rest of it, I can't question the players' motivation to win the game because it was quite obvious."
Brighton captain Lewis Dunk to SportNews: "It was probably the best football we've played all season for the first 20 minutes. Then they changed their press and we couldn't quite get to grips with it. They went man-to-man and we couldn't understand how to get out of it enough.
"But in the first half, we were the better side but in the second, we had to dig deep. It's always a tough place to come here.
"Sometimes you have to win a bit ugly and that's what we did today. We had a lot to resolve from last year and we did that so it's a nice feeling."
Brighton head coach Fabian Hurzeler to SportNews: "Very happy for the team, for the staff, they worked hard this week and during the game.
"We started really well. We created chances, we defended really well, then we deserved the lead.
"In the second half, we struggled a little bit. Nottingham Forest bought on some real quality and we suffered a little bit, but we stuck together, we defended and attacked together. In the end, we deserved to win."
