Launceston claimed the bragging rights by defeating Cornish rivals Redruth 31-10 at Polson Bridge.
The home side ran in five tries, two from Kieron Lewitt and one each by Liam Yeo, Tim Mathias and Lewis Paterson.
And although Dean Bonds and Chris Fuca replied, Redruth were clearly second best after the interval.
"What a super performance, every single player and all the supporters stepped up, we needed this," Launceston coach Tom Rawlings told BBC Radio Cornwall.
"Credit to the Reds, they beat us 2-0 last year, home and away, and our task was to go out and make this place a fortress.
"Defence was superb and attack was even better and we fired on all cylinders against a very tough Reds pack and some decent backs."
Opposite number Chris Fuca admitted his side had ended up chasing the game after a good start by the Cornish All Blacks.
"Launceston thoroughly deserved their victory and played some really nice rugby on the day," he said.
"At times we tried forcing the play and it didn't really pay off for us, and that came after such a good start from them.
"We never really got a strong enough platform to kick on and build our dominance in the game."
The win put Launceston ninth in the National Two South table, four points and five places ahead of Redruth.