Premier League champions Liverpool left a lead twice while Brighton fought in style to win a victory that increases their slim hope for securing European football next season.
Replacement Jack Hinshelwood turned out to be the match winner because he had an immediate impact and went to Matt O'RiLey's cross in the 85th minute, with the aim after a check of the video assistant referee (VAR) after it was originally ruled outside.
The Reds led 1-0 and then 2-1 during the break, before the sea lions recovered well to move eighth in the table, three points above Brentford.
In an entertaining match at Amex Stadium, Liverpool took a ninth minute lead through Harvey Elilott after good work by Conor Bradley, before Yasin Ayari equalized with a low strike.
But Dominik Szoboszlai restored the benefit of the Reds in a happy way.
He and Elliott combined to take a fast free kick, and from the right side of the penalty area, Szoboszlai apparently tried a cross in the box, only for the ball to fly over the head of house goalkeeper Bart Verbruggen in the net.
Alisson produced an excellent fingertip to deny Danny Welbeck, but could not do anything about the strike by Kaoru Mitoma when he showed a great technique to bring it 2-2 for the winner of Hinshelwood.
The seagulls travel to Tottenham on the last day of Sunday, and the team that ends the eighth can qualify for the UEFA Conference League.
However, to make that happen, Chelsea should beat in the final of 2025 on Wednesday 28 May and then finish seventh in the Premier League, or sixth as long as Newcastle subsequently became seventh.
Line-ups
Brighton XI: Webster, Welbeck, Pervis Estupiñán, Mats Wieffer, Jan Paul van Hecke, Bart Verbruggen, Yasin Ayari, Simon Adingra, Carlos Baleba, Brajan Gruda, Yankuba MINTEH
Subs: Veltman, Dunk, Igor, Matt O'RiLey, Kaoru Mitoma, Carl Rushworth, Diego Gómez, Jack Hinshelwood, Harry Howell
Liverpool XI: Alisson, Salah, Tsimikas, Konate, Gakpo, Chiesa, Szoboszlai, Gravenberch, Elliott, Quansah, Conor Bradley
Subs: Endo, Van Dijk, Robertson, Joe Gomez, Kelleher, Alexander-Arnold, Luis DÃaz, Nunez, Curtis Jones