Heslerton 2nds and Cloughton 2nds both collected comfortable wins to seal their promotion from Division Four.
Heslerton cruised past fourth-placed Filey 2nds in a 10-wicket win.
Filey were all out for just 60, Matty Webster and Marc Dring doing the damage with 5-24 and 5-29 respectively.
They had no trouble making their way to 63-0 in reply, Webster hitting 33 not out and Ian Dade 29 not out.
Their win keeps them 10 points adrift of second-placed Cloughton 2nds, who also cruised to a 20-point win and promotion in the process against Ganton 2nds.
Ganton were all out for just 77, Ben Rowe taking 4-17 and Mark Pryce 3-26, before skipper Liam Salt plundered an unbeaten 52 in his side's 78-1.
It was a day to forget for struggling Ravenscar 2nds, who were bowled out for just 34 in their hefty defeat at home to Mulgrave 2nds.
Mulgrave made it to 150-7 declared, Chris Spenceley hitting 46 and Simon Kipling 32, while John Nelson took 4-32 and Andy Edgar 2-33.
The hosts were bundled out for just 34 in reply, Luke Spenceley grabbing 5-14, Nick Gibson 2-13 and Aidan Duell 2-3.
Paul Waring and Harry Gargett-Hilton were the star men as Thornton Dale 2nds beat Sherburn 2nds by 57 runs.
Waring hit 66 in Dale's 152-7, supported by 39 from Tom Snowden, while Dan Bean took 4-41.
Sherburn struggled with the bat in their reply though and were all out for just 95, Gargett-Hilton taking 5-43 as only Simon Boyes (51no) and Ashley Oldroyd (23) got going with the bat.
Wykeham 2nds cruised past Muston 2nds.
Muston posted 89-7, Dave Meer hitting an unbeaten 45 as Robin Shepherdson took 3-13.
Wykeham then cruised to 90-3, Steve Eyre remaining unbeaten on 33.
Scarborough Nomads and Forge Valley 3rds conceded their games against Wold Newton 2nds and Scalby 3rds respectively.
Ganton secured promotion from Division Two with victory against Ravenscar.
Will Bradley hit 35 and Richard Bannister 26 as Ganton made it to 147-8, Jon Murrell taking 3-19, Binooj Bhas 2-42 and Freddie Barker 2-44.
Bradley then shone with the ball as he took 3-18 as Ravenscar were dismissed for 75, despite Joe Bayes hitting 43.
Freddie Bradley (2-2), Atul Palakattil (2-1) and John Bannister (2-8) all shone with the ball to help Ganton secure promotion.
Fylingdales moved back into third place as they beat Ebberston 2nds by 30 runs.
Graham Kettle hit 56 and Rob Grove 28 as Dales managed 153-5 at tea, and despite Mike Horsley's 38 and 25 from Sam Hardie after the interval, 3-30 from skipper Barry Heyes helped restrict Ebberston to 123-7.
Cayton 2nds beat Wykeham 2nds by 77 runs.
John Hodgson hit a crucial 29 as Cayton made it to 132-8, Chris Remmer taking 4-43.
Wykeham had no answer to the bowling of Simon Glave (4-26), John Crowe (3-7) and Daz Jones (3-21) in reply as they were all out for just 55, Tom Poor hitting 25 of those.
Sewerby 2nds conceded their game at league leaders Scalby 2nds, and struggling Scarborough 2nds conceded their game at Kirkbymoorside.
Darrol Lewis' 82 helped fire Seamer 2nds to promotion from Division Three as they beat third-placed Forge Valley 2nds by 81 runs.
Lewis top-scored in Seamer's 164-8, Connor Myerscough adding 27 as Aaron Fox 93-8) and Sarfraz Ali (3-43) impressed with the ball.
Myerscough then took 5-42 and Steve Winwood 2-25 as Valley were all out for just 83, Tyler Beck hitting 37.
James Perrett smashed a stunning 35-ball 113 not out to help Scarborough Rugby Club to a one-sided 183-run win against Muston.
Perrett raced to three figures in just 33 balls, his half-century coming off just 17 deliveries, as the away side managed 214-4 declared, Marcus Edwards also hammering 68.
Edwards then got to work with the ball, taking 4-9 as Perrett also grabbed 3-20 to ensure Muston were all out for just 31 in reply.
James Boyes shone with the ball as Pickering 3rds cruised to a 10-wicket win at Flamborough.
Boyes' 4-9 plus 2-18 from Luke Shepherd and 2-19 from Tony Evans ensured Flamborough were 73 all out before Danny Walker and Owen Cowton remained unbeaten on 43 and 23 to help the Pikes to 74-0.
Flixton 3rds were struggling on 24-4 when rained stopped play in their game at Nawton Grange 2nds, Peter Wilson having taken 3-5.
Cayton 3rds were on 76-3, Shafik Iqbal having hit 49, when rain halted their game at Snainton.