Ireland’s side pushed for a late equaliser but it wasn’t to be as Cardiff left the south coast with another victory.
The game became stretched and Courtney Richards nearly found the equaliser when his deflected free-kick dropped onto the bar, and Albion’s best opening fell to Dickenson after Charlie Harris played the forward through, but the striker didn’t get the connection he desired as he dragged wide.
Last week’s match winner Rhys Healey was denied twice at the start of the second half, firstly by the legs of Christian Walton before the rebound was blocked by Glen Rea. Walton was again on hand soon after to push Joe Mason’s strike around the post.
But the visitors soon made the breakthrough as John Brayford’s low cross was expertly guided in at the near post by O’Sullivan.
Courtney Richards dragged wide for the Seagulls but Albion had Vitalijs Maksimenko to thank shortly after, the Latvian blocking bravely to stop Theo Wharton’s volley.
Emile Asmundsson had the first effort at goal that dropped just over in the third minute, before Brennan Dickenson’s turn of pace created space down the left, but Solly March could not direct the cut-back on target.
Last week’s cup fixture produced seven goals but Tommy O’Sullivan’s solitary strike was all that was separated the two sides on this occasion.
Cardiff City claimed their second win in a week at Culver Road to end Albion’s unbeaten league record.
RB: Hunt (Deen 46)
CM: Asmundsson (Benham 65)
FW: March (Davis 46)