Brighton's first league win of the calendar year eased their relegation worries a little as they moved level on points with West Ham United in the Premier League table.
Goals from Glenn Murray, Jose Izquierdo and Pascal Gross gave the resurgent Seagulls a much-deserved win against a West Ham side who failed to live up to the levels of which they are capable.
Javier Hernandez's equaliser was the only moment of quality for the Hammers as they lost in the league for the first time since before Christmas.
Brighton made only one change from their draw at Southampton in the week, with Anthony Knockaert returning to the team in place of Solly March. Leonardo Ulloa was on the bench after returning to the club in January.
West Ham were unchanged from their draw with Crystal Palace, although Jordan Hugill was among the substitutes following his deadline day move from Preston.
Brighton started on the front foot and took the lead within just eight minutes. Pascal Gross played a brilliant through-ball to Glenn Murray who kept his cool to slot past Adrian.
It was Murray's fourth goal of 2018 and he was clearly high on confidence. He was on the end of some nice passing again minutes later, and sent in a low goalbound effort which was blocked.
Brighton looked a threat every time they came forward, and could have had a penalty when Knockaert's goalbound effort struck the arm of Angelo Ogbonna. It was at point-blank range, but it did clearly hit Ogbonna's arm and Brighton could count themselves aggrieved.
Their sense of injustice intensified a few minutes later when West Ham delivered a sucker-punch of an equaliser. It was a nice goal, with Joao Mario finding Javier Hernandez who waited and waited before finally smashing past Matt Ryan and into the top corner.
Brighton could have restored their lead soon after if Knockaert had shown a little more intelligence. First, he didn't slip in Murray for what would have been an easy chance, and then he failed to capitalise on a Mark Noble error, slicing his effort harmlessly wide.
Knockaert also overran the ball as Brighton sought to take advantage of a good counter-attacking opportunity, and West Ham would have been pleased to get in at half-time with a share of the spoils that they barely deserved.
The second-half started in much more even fashion than the first, but again it was Brighton who drew first blood.
A corner was only half-cleared and from the edge of the box, Jose Izquierdo bent an absolute howitzer of a shot past the despairing dive of Adrian and into the top corner.
If a huge cheer had greeted the goal, an equally big one was to come with 20 minutes to go. Ulloa replaced Murray for his first home appearance at the Amex Stadium since he left the club in 2014.
And just moments later, Brighton had breathing space, although Ulloa wasn't involved. James Collins poor clearance was straight to Davy Propper, who fed Gross. The German made space on the edge of the box before arrowing a shot into the corner of the net.
Gross nearly had his second and Brighton's fourth shortly after, but his curled effort was pushed away by Adrian. Hugill then replaced Sam Byram for the visitors, making his debut in difficult circumstances.
Brighton saw the game out with ease as West Ham's challenge faded, and they really should have won by more. Substitute Beram Kayal's shot-on-the-turn was pushed away by Adrian, with Solly March skying over on the follow-up.
But that could not spoil Brighton's day, and a jubilant Amex crowd serenaded their team to the end as they moved three points clear of the relegation zone.