A fisrt half own goal by Marlon Brooms was enough to give the Seagulls the points and increase the pressure on Prestons under fire manager Craig Brown.
Brooms, replacing the injured Graham Alexander, was standing on his own line at the far post when he headed in an in swinging corner by Darren Currie in the 30th minute.
The result rewarded the ingenuity of Brighton manager Mark McGhee after his team had taken only one point from their opening four games and lost at home to Bristol Rovers in the Carling Cup.
He played young defender Adam Virgo as an emergency centre forward alongside the prolific Leon Knight and gave central midfielder Dean Hammond his first start for nearly 2 years.
Both played their part in an untidy victory against a toothless Preston.
Virgo could have scored on a couple of occasions in the first half.
He directed a free header from across by Dan Harding straight at Harding's England under 21 team mate Andy Lonergan.
The Preston keeper also saved another Virgo header from across by Nathan Jones, who was recalled on the left side of midfield at the expense of Albert Jarrett.
Brighton could have been out of sight by half time, Alexis Nicolas nodding just wide after Lonergan punched clear another in swinging corner by Currie.
Preston improved after the break as Brown threw on Andy Smith as a third striker.
The substitute was unmarked when he headed straight at Michels Kuipers from a David Healy cross.
Kuipers came to the rescue for Brighton 4 minutes from time with a feet first save from Richard Cresswell, Healy blazing the rebound wide.
Hammond and young defender Adam Hinshelwood then saved Brighton in a frantic finish with last ditched tackles inside their own area on Healy.