A flurry of first-half goals saw our young Reds twice lead during the opening 45 minutes, with Joe Hugill's deflected effort at goal turned into his own net by Sam Packham inside 60 seconds.
Ruairi McConville then levelled the game just three minutes later for the Albion, before Noam Emeran's superb free-kick saw United take the lead once more.
Cameron Peupion equalised for the hosts on the stroke of half-time with the score at 2-2, before Mark O'Mahony's goal midway through the second period ensured the Seagulls took all three points.
United flew out of the blocks and took the lead inside the first minute, as Hugill's strike deflected off Peckham and flew past Tom McGill to make it 1-0 to the Reds.