Chances were few and far between in the opening minutes, with Richard Smallwood's shot that was saved by Casper Ankergren in the 11th minute the first real effort by either side.
Brighton were making the attacking moves at the Riverside, while their hosts were resorting to committing fouls to stop the Seagulls.
The pattern continued for the rest of the first half that left much to be desired from both sides, with Andrew Halliday's effort from close range for Middlesbrough on 43 minutes giving hope of a more entertaining second 45 minutes.
Indeed, the second half started on a bright note as Scott McDonald shot just wide from inside the area for the home team.
However, it was Brighton who surged ahead on the hour mark through Andrea Orlandi, who latched onto Dean Hammond's pass to slot home from inside the Middlesbrough six-yard box.
Orlandi had a decent chance to add to his tally in the 74th minute from the edge of the area, but this time he failed to keep his shot on target.