Crystal Palace staged a smash-and-grab raid on the south coast to beat rivals Brighton 3-1 and move four points clear of the relegation places in the Premier League on Sunday.
A double from Ismaila Sarr, his first since joining the club in the summer, and a Trevoh Chalobah strike secured the points for Oliver Glasner's side in the so-called "M23 derby" at the Amex Stadium.
An own-goal from Palace defender Marc Guehi gave the home side a late consolation.
It was the first time Palace had scored three goals in the Premier League this season and their first back-to-back away win for 18 months, moving them up into 15th place on 16 points.
A first home defeat of the season for Fabian Hurzeler's side saw them slip two places into ninth spot and means they have now gone three games without a win.
Chalobah opened the scoring for the visitors in the 27th minute as he rifled the ball into the roof of the net from close range after a goalmouth scramble following a corner.
Sarr doubled Palace's lead after 33 minutes when Tyrick Mitchell swung in a superb cross following another defensive mix-up by Brighton and the Senegalese forward burst into the box to finish with a smart angled header.
Hurzeler rang the changes in the second half, with Julio Enciso in particular making an impact, with Palace goalkeeper Dean Henderson forced into making a string of good saves.
But the Eagles made the game safe after 82 minutes when Sarr beat the Brighton defence to race on to substitute Eddie Nketiah's pass before slotting home past Bart Verbruggen.
Brighton nicked a scrappy goal back in the 87th minute when Guehi deflected the ball into his own net from a corner.
Palace keeper Henderson told Sky Sports: "It's absolutely massive. The fans have been patient with us this season. We are in a false position, we have great players and today it all clicked.
"We knew they would come out [in the second half] and it would be hard. Luckily I helped the team today.
"When you're in that moment, you feel good, you feel unbeatable. Thankfully we got the third but unfortunately we conceded at the end.
"They [the fans] have been on at us all week, telling us you can be a hero if we win this game."
Brighton manager Hurzeler said: "The goals we conceded are too easy. You can't concede these easy goals.
"I think we showed a good reaction in the second half, we had some big chances but then the game is getting more and more difficult because they are getting more and more compact.
"It is tough but we have to learn from these things and improve.
"In the end we had the chances, I think the goalkeeper saved two or three big chances but we were not clean enough in the final third. We missed the killer instinct to get the goal.
"It is tough because we have had several of these days where we have to talk after a bad experience. You have to let these lessons teach you and find a solution."
