Salesbury held up their part of the bargain as they beat Euxton in their final game of the season.
But wins for Cherry Tree and Earby mean they retained their place in the top two and claimed promotion to section A.
Cherry Tree - 11 points ahead of Salesbury at the start of play - needed just two points from their game at home to Edenfield to seal top spot, while the Red Caps were five points behind Earby ahead of their clash with Brinscall.
Tree beat Edenfield by three wickets as Naz Iqbal hit 52, after Nigel Robbins took 5-78 as Edenfield were dismissed for 173.
And Earby skittled Brinscall for 97 as professional Dave Crotty took 5-23, before sealing a nine-wicket success.
Salesbury, meanwhile, dismissed Euxton for 115 - of which Sam Tolley made 53, before easing to victory by seven wickets.
Tolley opened the batting, and was seventh man out at 93 as wickets fell around him.
Tolley and Louis Sweeney shared 44 - the best stand of the innings - for the sixth wicket after the hosts struggled to 39-5.
Salesbury mopped up the tail as Shabaz ended with 3-32, Sam Bristol 3-4, Josh Bristol 1-19 and skipper Steve Brown 1-4.
The Red Caps eased home in reply, with James Watson hitting 24, Liam Parkinson 19, Matthew Kleimveldt 46 not out and Ben Rigby and unbeaten 18.