NLR A's Jonathan Green, who missed a gilt-edged chance to add a seventh, told JC Sport: "It was a real battle for us, especially in the first half when there was very little to separate the sides.
"Although we went ahead inside the first five minutes, the B’s showed real character in dragging themselves back into the game, winning most second balls in midfield and creating chances. They have a real threat going forward and it was clear to see why they are top of their league.
"Thankfully we continued our recent habit of really going through the gears in the second half and once we got going some of the football from the boys was a joy to watch. It’s great to be in the hat for the last eight."
Raiders B-team boss and club chairman Jonathan Adelman was proud of the performance from his men, for whom Simon Buchler registered a quality consolation strike.
He told JC Sport: "The final scoreline is a little harsh on us given how well we competed, especially in the first half where we matched a great side every step of the way.
"Ultimately our A's pass the ball so quickly and have such great movement off the ball that we just ran out of steam and they clinically took advantage of their chances.
"We came back strongly towards the end and overall despite the scoreline I'm pleased with the performance and attitude - it bodes well for the rest of our league campaign."
After singling out Matt Stock as "the best player on the pitch", Adelman added: "The A's have an abundance of talent and I hope this year they secure the silverware that their talent and performances deserve."