The more physical and energetic Lady Eagles led from start to finish, holding an 11-point advantage at halftime. Barrington led by double digits through most of the second half.
South Kingstown cut the lead down to seven with minutes to go before senior guard Kelly Thayer netted a pair of free throws to ice the game.
Eagles senior forward Maura Kelty led all scorers with 20 points. Junior guard Sarah Middleton added 10 points.