North Launceston has extended its winning run over Launceston to 16 matches with a 32-point win on Good Friday.
Playing in front of a brimming crowd at Windsor Park, the Northern Bombers were inaccurate but comfortable winners in a 12.20 (92) 9.6 (60) result that ensured they enter next weekend's grand final rematch against Lauderdale unbeaten.
Reliable defender Arion Richter-Salter pocketed the Adam Sanders medal for a workmanlike performance and also put one hand on the mark of the year award with a towering leap over Launceston ruckman Hamish Leedham.
The grab typified a one-sided second quarter that drew a line between the two teams after Launceston took a nine-point advantage into the first break.
Goalless in the first term, the Northern Bombers turned their forward 50 into a maximum-security prison for Sherrins in the second, kicking 5.8 to 1.1 as the Blues struggled to find a second kick out from defence.
A run of seven consecutive points and impressive tall Alec Wright's first on the stroke of half time were all that kept the Blues in the contest after Taylor Whitford kicked two in three minutes late in the term.
Neither side was able to get on top in the second half, but the Bombers never looked like dropping a derby streak dating back to August 2013.
"The second quarter we owned and dominated we just couldn't put the score on the board," Whitford said.
"Kicking so many points probably kept Launceston in the game to be honest - the third quarter was a bit of an arm wrestle and we probably should have kicked away further in the last.
"On the whole, it was better than what we've produced in the first few weeks but we've still got a while to go to get where we want."
The Bombers again looked a cut above in their back half as Richter-Salter, Jay Foon and Liam Davies linked up with precision to spark forward thrusts.
Josh Ponting and Whitford were both clean with ball in hand, James Curran looked lively in his first outing and Jack Rushton wove in and out of the game with two goals in the last term.
Dakota Bannister (four goals) looked ominous in his first game back and could have combined for plenty more with Ben Elmer (two goals) save for a handful of missed chances.
The Bombers' scoreboard read eight more behinds than goals for the second game running, but Whitford said he wasn't worried by the wasteful kicking just yet.
"If it becomes a pattern then it's probably going to be looked at," the reigning player of the year said.
"Two games out of three we've scored more points than goals - three's a pattern - so if it happens again then we'll have to look at where our entries are coming from.
"But we missed some easy shots today so I'm probably not too worried about that."
Blues coach Mitch Thorp was again left to rue a performance where his side matched it with a top-three opponent for three quarters, with just one point separating the two teams either side of the second term.
Grant Holt had a hand in two goals late in the third which cut the margin back to 20 points, but a roosting 45m set shot from Brad Cox-Goodyer on the siren took the heat out of a potential fightback.
"In the second quarter they got hold of us and we couldn't get the ball back into dangerous parts of the ground," Thorp said.
"They locked it in their forward half really well and had a lot of shots as well, the third and the fourth I thought we really had that effort that we've prided ourselves on all year and we never dropped away at any stage.
"So while we're really disappointed, it's just where we're at at the moment against the very good sides in the competition - Glenorchy, Lauderdale, North Launny - they have that one quarter where they get hold of us and we can't quite get into it.
"That's our challenge so we'll own it and keep working on it together."
Big-bodied midfielder Jobi Harper was again a huge presence around the ground, adding three goals to a collection of contested grabs, while Jake Smith and Casey Brown again teamed up well to lead the Blues' back six.
"Jobi was clearly our best - he's had 35 touches, kicked three goals and been tagged - he's our captain for a reason, he leads by example," Thorp said.
"I thought Jake Smith was excellent off half-back and took the opposition best forward every time that player was there and did a really good job defensively."
In the other TSL match, Tigers recorded their first win with a 15.10 (100) to 5.10 (40) win over North Hobart.