The Pirates have reduced the deficit to nine points at the break. Aaron Penberthy gave them a fourth minute lead with a drop goal.
Rob Cook kicked a penalty, and it was his storming run in the 23rd minute that set up Matt Evans for the only try of the half, which Cook then converted.
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Some 20% of carriageways in England and Wales have less than five years of life remaining before they become unusable, researchers said.
Icy conditions expected after a freezing night. The far west will enjoy sunny spells while the rest of the region sees increasing cloud.