Nelson claimed a five-wicket win at Rishton on Saturday.
And with two games remaining, Russell Bradley’s side are in a straight shootout with Clitheroe, Burnley, Crompton, Rochdale, Todmorden and Enfield for a place in the Lancashire League’s top division next year.
Leaders Walsden, Lowerhouse, Ramsbottom, Darwen, Norden, Church and Accrington have confirmed their place in the top half, with seven clubs battling for the remaining five slots.
And Nelson did their cause no harm at Blackburn Road.
Rishton won the toss and chose to bat, and sub professional Daryn Smit (pictured) took 4-37 as the hosts were dismissed for 124 in 46.1 overs.
Caleb Grant removed Sajid Patel with his first ball – the first of his 4-40.
And Rishton were indebted to professional Mansoor Amjad, who top-scored with 54 from 93 deliveries.
Only Craig Smith, who made 15 from 58 balls, Richard Fox (16) and Luke Eddleston (12) could join him in double figures.
In reply, young Matthew Pettinger (48) and Jack Bradley (33) put on 60 for the first wicket, and Smit added 19 as Nelson passed the target in 44.1 overs.
Sunday’s game at home to Lowerhouse was abandoned.
Nelson are at Milnrow on Sunday, with their final game at Rochdale next weekend.
Colne suffered a seven-wicket defeat at home to Burnley on Saturday, having been bowled out for 84.
Sub professional Dieter Klein took 5-23 and Cole Hayman 3-24 for the visitors, as Kenton Rhodes made 23 and David Spokes 19.
Rhodes took 2-32 in reply, but Burnley eased home in 16.4 overs as Liam Bedford hit 31, Matt Roberts 17 and David Brown 22.
Colne host Crompton on Sunday at the Horsfield, before signing off for the season a week on Sunday at Great Harwood.