Glenn Murray scored twice as Brighton gave their survival hopes a shot in the arm and brought Swansea's revival to a halt.
Murray's double and goals from Anthony Knockaert and Jurgen Locadia helped secure a 4-1 victory and a valuable three points for the hosts, as the Swans' 10-game unbeaten run in all competitions came to an end.
The World Cup may be a pipe dream for 34-year-old Murray, but he now has 10 Premier League goals this season and only three Englishmen - Harry Kane, Raheem Stirling and Jamie Vardy - have scored more.
Brighton have been in decent form, unbeaten in their last five outings, but they still need points on the board sooner rather than later with a daunting run-in which sees them face Tottenham, Manchester United and Liverpool in their final four matches.
So a home meeting with another side battling against relegation was seen as a 'must-win' game for Chris Hughton's men.
They threatened first with a lightning counter-attack led by Knockaert, who crossed towards Pascal Gross at the far post, but the German frontman opted to take a touch before shooting and allowed Tom Carroll to make a last-ditch block.
From the resulting corner Jose Izquierdo blazed over, but the Seagulls did not have to wait long to make the breakthrough.
In the 19th minute Mike van der Hoorn caught the back of Murray's leg, sending the striker tumbling to the deck.
Murray stepped up and confidently tucked away the spot-kick, sending Lukasz Fabianski the wrong way.
Swans boss Carlos Carvalhal clearly felt his side needed a different approach and made a bold substitution nine minutes before half-time, taking off Nathan Dyer and putting Andre Ayew up front with his brother Jordan.
And both sides were denied by the woodwork before the break, Lewis Dunk thumping a header against the crossbar and Jordan Ayew firing against a post.
Early in the second half Seagulls goalkeeper Mathew Ryan dived full stretch to his left to palm away Ki Sung-yueng's drive.
At the other end Murray bundled in a cross from Knockaert, but he was marginally offside and the goal was ruled out.
However, Murray was not to be denied in the 69th minute after some fine interplay between Izquierdo and Gross.
Izquierdo reached the byline and cut the ball back to where Murray was waiting eight yards out to sweep the ball home.
Four minutes later Gross played in Knockaert, who drove low with a smart finish across Fabianski.
Swansea substitute Tammy Abraham created an 85th-minute consolation with a long-range effort which deflected in off Dunk.
But Brighton's record January signing Locadia, on as a substitute, completed the scoring when he turned in a Dale Stephens shot with a minute remaining.