Karlan Grant scored twice and missed a penalty as West Brom rounded off a disappointing season with a thumping win over bottom-of-the-table Barnsley.
Grant gave a dominant home side the lead from the spot after Jayson Molumby was felled in the area by Clarke Odour and Adam Reach made it 2-0 when he ran onto a long ball and looped the ball over keeper Jack Walton.
The Baggies, who were top of the Championship table in October, went 3-0 up after the break when defender Matt Clarke showed great composure to slip the ball under Walton from close range after good work by Grady Diangana.