Douglas B booked their spot in the Manx Plate semi final with a comfortable win over a depleted Ramsey B side.
They came out 35-5 winners at a slightly damp Port-e-Chee.
The high point for Douglas was a hat-trick from Jack Moore, a brace from Nathan Pierce and a solitary try from skipper Richard Melia from a modest 40 yards out.
Castletown lost 50-14 to Vagabonds B at Poulsom Park as the Shimmin Wilson Manx Shield competition nears its end.
The defeat for Town means they are confirmed with the wooden spoon this season, while Vagas, after a slow start, could yet finish runners up.
Mick Shipley and Dave Akkulugadu both picked up tries for Town with Gary Stephenson adding two conversions.
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