Douglas beat Oldershaw 57-0 at Port-e-Chee to give them a much needed boost before the Christmas lay-off.
Andrew Evans bagged five tries as Douglas went on the rampage against struggling opponents.
There were also tries from Simon Heggs, Will Latta, Callum Carine and Bryn Snellgrove who also added six conversions.
Southern 100: Todd retains solo championship title and Crowe Brothers set sidecar lap record
Action on the Billown Course comes to an end for 2025
Southern 100: Wins for Todd, Browne and newcomers during morning races
Four races still to take place this afternoon
Southern 100: Two wins for Davey Todd as racing gets underway
Rob Hodson, Paul Cranston and the Crowe Brothers also secure victory
IoM women's football eyeing top prize in Orkney
Captain and Manager confident in abilities to take Island Games gold