Having made a goalscoring return from injury against Manchester City two weeks ago, Joao Pedro celebrated his first start since August with a goal inside four minutes.
He combined well with Danny Welbeck before Georginio Rutter took up the mantle and forced a save from Kepa Arrizabalaga, who could only parry the strike to Pedro who tucked home the rebound - the first time Bournemouth had conceded a first-half goal at the Vitality Stadium this season.
That aside, the Cherries dominated the opening half, beginning with Antoine Semenyo narrowly missing the bottom corner inside 90 seconds, before Justin Kluivert and Evanilson produced smart stops from Bart Verbruggen.
The same three attackers combined again for what the home side thought was an equaliser three minutes before half-time, but Kluivert was offside from Semenyo’s through ball before he squared to Evanilson.
After scoring in the fourth minute of the first half, Fabian Hurzeler’s side repeated the feat in the fourth minute of the second half.
This time, Pedro was the provider, threading a delightful through ball into the path of Kaoru Mitoma, who steered it past Kepa and into the bottom corner with his first touch.
Bournemouth, who would have pulled a goal back almost immediately had Evanilson not missed the target from six yards, were handed a lifeline just before the hour mark when a second yellow card shown to Carlos Baleba reduced the Seagulls to 10 men.
That swung momentum firmly towards Andoni Iraola’s side, leading to further opportunities for Semenyo and Kluivert.
The wet conditions nearly caused havoc in the final 15 minutes when Evanilson’s powerful header slipped through Verbruggen’s gloves, but the goalkeeper recovered before the ball crossed the line.
That looked to be that until David Brooks finished off a fine move in stoppage time to halve the deficit.
However, Bournemouth have now lost back-to-back fixtures, as they drop to 13th following the defeat.
Brighton held on to take all three points for the fourth time in their last five meetings.
Flashscore Man of the Match: Joao Pedro (Brighton & Hove Albion)
