The bonus point they picked up on the 14-8 loss keeps them one clear of Bury St Edmunds in the league and they also have two games in hand over those around them.
A tight and physical match at Westcombe could have gone either way.
It took 35 minutes for the first score, the conditions also being something of a leveller.
Guernsey spurned a couple of kicks at goal before Combe’s scrum half Ben Fryatt took full advantage of a slick offload to sprint through the gap to score close to the posts.
Outside half Nathan Wyman kicked the conversion in the swirling wind to give the home side a 7-0 lead.
Raiders responded just before halftime.
Their lineup had been malfunctioning, but this time a more accurate throw gave No 8 Carter Hackett the opportunity and he finished in the corner. The conversion went awry.
Combe had the advantage of the conditions in the second half.
It was in the 55th minute that centre Leo Jowett stretched their lead after being put into space by Toby Wallace.
Raiders centre Ciaran Mcgann hit a penalty from in front of the posts to make it 14-8 with three minutes remaining, but 13 man Combe held out for their third win on the bounce.
Raiders return to action against Havant on Saturday 11 January at Footes Lane, the start of a busy run of fixtures.
