CASEY Demons have secured victory in the 2017 AFL Victoria Development League Grand Final with a 12-point win over Williamstown on Sunday.

Casey Demons 13.16 (94) defeated Williamstown 11.16 (82) in a tight contest at Fortburn Oval in Port Melbourne.

The victory caps off an impressive season for the Demons who also finished the year as minor premiers.

After trailing Williamstown by 16 points at quarter time, the Demons kicked four unanswered goals in the second term to lead by nine points at half time.

Williamstown bounced back to hold a five-point lead at the last break before Mykelti Lefau from the Demons kicked the sealer at the 30-minute mark of the final quarter to cement Casey’s victory.

It was the third consecutive occasion that the Demons had defeated Williamstown this season.

Sunday’s Grand Final marked the conclusion of the Development League after it was announced that the competition would wrap up at the end of the 2017 season.