Plymouth ran out 113-82 winners on the south coast as the visitors fought hard before slipping away.
The home side started off strongly and jumped into a commanding early lead off the back of some hot downtown shooting, as Daryl Corletto dropped three early triples.
In front 30-20 at the end of the first period, they briefly extended their advantage but they were reeled back as Giants came alive.
Led by Sam Toluwase, the Giants found some real rhythm and levelled just before the break at 44-44.
However, Raiders headed into the break 48-44 up and took control in the third as their three-pointers started to drop again.
The Raiders led 77-59 going into the fourth period and kept their foot on the gas to secure the win.
Jerelle Okoro (16) led the way for the Giants with Sam Toluwase had 13 and Callum Jones, Donotas Visockis and Richard Bell had 10 apiece.