League leaders Flixton and reigning champions Atherton will be joined in the top section of the Bolton Association by Daisy Hill, Bury, Elton and Walshaw as the league splits into three next weekend.
The six teams will now play each other once as they compete for the title and Lancashire Knockout places, with points gained being added to those already accrued in the first 17 games.
Six bonus points were enough to secure Walshaw's place in the top division in the final game before the league split despite a three-wicket defeat to second-placed Atherton.
Danny Hornby top-scored with 64 as the Bury side batted first to total 199-9 with Jamar Griffiths taking 3-72.
Roshon Primus led the Atherton reply, top-scoring with 58 as the visitors chalked up 200-7 to take the victory with the best bowling coming from Steven Holt 3-58 and Liam Riley 3-52.
Tushendra de Zoysa's century for Blackrod was in vain as the Vicarage Road men collapsed to 188-8 from their 48 overs at Winton to miss out on a top six spot.
Simon Brittain's 3-37 and David Marchment's 2-40 were the best bowling figures for the hosts who posted 190 for the loss of just one wicket in reply.
Rick Johnson top-scored with 80, with Rowan Bricker (61) and captain Mike Stevens (40 not out) adding to the total as the hosts raced to a nine-wicket victory.
Simon Ward's top 50 led Elton to victory at Little Hulton and a place in the top section.
Ward top-scored with 78 as the visitors notched up 150-2 in reply to the home side's 149 all out as Elton became the third Bury side to clinch a place in the top six as they took advantage of Blackrod's defeat.
J Patel top-scored with 49 and Shaukat Patel hit 39 for the hosts.
A match-winning performance with the bat and ball by David Flanagan led Lostock to victory at Daisy Hill.
Having lost the toss, Lostock batted first and struggled to 103-7 with Stephen Hodgkinson, despite not taking a wicket, slowing the run rate with six maidens from seven runs in his 10 overs.
But it was the eighth-order batsman Flanagan who hit a half-century to steady the innings and also took seven wickets as the visitors won by 46 runs.
Amjid Khan was the pick of the Daisy Hill bowlers taking an impressive 5-29, including six maidens, but his efforts were in vain as top-scorer Flanagan notched up 66 and Connor Hicklin also batted his way to 40 as Lostock totalled 161. Mark Atherton took 3-54 off his 10 overs.
In reply, Mark Wood hit a half-century for the St James' Street men, as they secured third place ahead of Bury, before he was dismissed by Flanagan, who tore through the batting order taking 3-37 off 13.3 overs as the home side were skittled for just 115 runs.
It was a case of after the Lord's Mayor show for Simon Belston's Bury as last weekend's Cross Cup victors crashed to a 58-run home defeat against Swinton Moorside.
The visitors batted first with David Flatley hitting 49 as they totalled 176-9. Jordan Belston was the pick of the Bury bowlers taking 3-27.
A five-wicket haul from Sriram Krishnamurthy (5-59) and four wickets from Jack Wood (4-30) saw the home side skittled for just 118 runs in reply.
A century from Luke Perry saw league leaders Flixton reign victorious from a high-scoring game at Worsley.
Perry top-scored with 111 not out and Anton Beckford also hit 57 as the visitors notched up 268-3.
Steve Hammond did the damage with the ball taking 4-80 as Himesh Silva 64 and Tom Othick's 55 not out was not enough for Worsley as they tumbled to 239-8 as Flixton won by 29 runs.
Travis Wordsworth hit a half-century in fifth-from-bottom Astley & Tyldsley's must-win match at Edgworth as they looked to secure a place in the middle section of the league next week.
Wordsworth top-scored with 64 as the visitors totalled 190 with Liam Watkinson taking 3-31 and Gareth Williams 3-42.
However, half centuries from Tom Fairclough (73) and Jaco Fourie (58) helped the hosts claim the 193 they needed for victory with the loss of just two wickets.
Despite Tom Foster top-scoring with 79, Adlington fell to a four-wicket defeat at Darcy Lever.
Pro Majeed Majid also hit 40 and Mark Halliwell (35) as the visitors posted 217 off their 48 overs with Alex Lee taking 4-72.
Nick Foure (66) and Chris Fenn (45) led Lever to victory as the home side totalled 218-6 with Karl Jones taking 3-32 and Foster 2-48.
A century from Sam Heeley and a top 50 from David Bowden led Standish to a 38-run win at Golborne.
Heeley top-scored with 101 not out with Bowden on 56 as the visitors notched up 212-7 from their 48 overs with Mark Farrar taking 3-32.
Bowlers Bowden (4-52), Heeley (3-28) and Chris Gunn (3-12) skittled the home side for 174 with Jamie Whittaker top-scoring with 45.
Blackrod 188-8 Winton 190-1.
Winton won by 9 wickets.
Adlington 217-7 Darcy Lever 218-6.
Darcy Lever won by 4 wickets.
Astley & Tyldsley 190 Edgworth 193-2.
Edgworth won by 8 wickets.
Flixton 268-3 Worsley 239-8.
Flixton won by 29 runs.
Little Hulton 149 Elton 150-2.
Elton won by 8 wickets.
Lostock 161 Daisy Hill 115.
Lostock won by 46 runs.
Walshaw 199-9 Atherton 200-7.
Atherton won by 3 wickets.
Swinton Moorside 176-9 Bury 118.
Swinton Moorside won by 58 runs.
Standish 212-7 Golborne 174.
Standish won by 38 runs.