Danny Welbeck’s first-half goal proved decisive as Brighton condemned Newcastle to their first Premier League defeat at home since January.
The result lifts the Seagulls up to fifth in the table while the Magpies remain eighth.
Brighton had spent most of the opening period on the back foot when Welbeck’s quick thinking made the difference.
The former England forward, who turns 34 next month, played a clever one-two with Georginio Rutter before placing the ball in the bottom right corner with the visitors' first effort on goal of the afternoon.
Welbeck, who was withdrawn on a stretcher late on after appearing to injure his back, has now scored five goals in eight appearances in the top flight this term.
However, Brighton’s victory was also down to some resilient defending coupled with profligate finishing from the hosts.
Eddie Howe's side carved out several promising openings with Alexander Isak and Anthony Gordon both going close but they were unable to find a way past visiting goalkeeper Bart Verbruggen.
Continued Welbeck renaissance boosts Brighton
While all the pre-match focus was on the return of Newcastle's talismanic striker Isak from injury, another centre forward, Welbeck, underlined his importance to Brighton.
The former Manchester United and Arsenal striker would undoubtedly have collected more than the 42 caps he holds for his country if it were not for a catalogue of injuries hampering him during his prime.
However, Welbeck, who, is - unusually - a couple of years older even than his manager Fabian Hurzeler, is enjoying a purple patch in front of goal as he enters the twilight of his career.
"If he continues to behave like he does, then he can play on for a long time," said Hurzeler, who confirmed Welbeck would undergo a scan after being caught in the back by Newcastle defender Fabian Schar's knee.
"We have another player who is an age of nearly 40 and he's still there and trying to be the best every day. That's the same for Danny.
"I knew [when I came] he had great talent and he's a great team-mate. He has a feeling for the dynamics of the team and he tries to connect the players. That's very important for me."
If you were to simply deduct Welbeck's contributions in the opposition penalty area this season, Brighton would be seven points worse off, hovering above the bottom three.
Instead they find themselves rubbing shoulders with sides with far bigger budgets who are chasing Champions League positions.
Brighton's steely defensive effort was also encapsulated late in the game as Lewis Dunk and Pervis Estupinan combined superbly to snuff out the danger posed when the ball reached Miguel Almiron eight yards from their goal.
Wasteful Newcastle pay the price
While Brighton will travel back to the south coast in a jubilant mood, Eddie Howe and his Newcastle team were left wondering how they had contrived to let three points slip away.
"I'm really frustrated because I thought our general performance today for 65 minutes was really good," said Howe.
"I think that's the best we've looked, the most dominant we've been in a game and, lo and behold, we have plenty of chances, don't take them. We only have ourselves to blame for that."
Newcastle largely controlled proceedings, with their dominance of the ball reflected in the possession statistics.
And Isak and Gordon - two players in line for new contracts – carried the side's main attacking threat.
However, England winger Gordon’s curling effort, which was tipped to safety by Verbruggen, became a precursor of what was to follow.
Isak, played expertly through on goal by Bruno Guimaraes, was also unable to beat the Netherlands international and his deflected shot after the break was also repelled.
Neither their flurry of substitutions or shots just after the hour mark brought any reward and when Dan Burn did lob at Verbruggen late on, a VAR review was not needed to see the Newcastle defender was well offside.
Newcastle failed to score a Premier League goal at home for the first time since the start of last term – a run of 22 games - and this consigned them to their second defeat of the season.
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