Sam Triffitt top-scored with an explosive 65 from just 42 balls, while Kristian Wilkinson added 45 and Rob Green 43 as the visitors posted 227-9.
Andrew Slaughter (4-13), Paul Kinghorn (3-15) and Andy Exton (3-26) then linked up to skittle Dale for 126 and wrap up their promotion success.
Staithes have won the Premier Division after having been handed their game against Bridlington 2nds.
Staithes travel to Filey on Sunday in their final game of the season.
Scalby slipped to third place after their seven-wicket loss at home to Ebberston.
Brett Cunningham’s 69 dominated the home side’s 155 all out, Gareth Edmunds adding 27, James Boyes taking 3-29.
Eddie Swiers’ powerful 92 from just 84 balls, including five sixes and seven fours, allied to Jordan Welford’s 43, steered the visitors to victory.
Mulgrave lost by six wickets at Cayton.
Chris Knight hit 34 and Chris Clarkson 30 as the visitors were dismissed for 122 in 26.4 overs, brothers Tom and James Ward bagging three wickets apiece.
Tom Ward capped a fine all-round day with a top score of 35 as Cayton secured the win, skipper Michael Dennis adding 34.
Filey won by six wickets at Seamer & Irton.
Skipper Gregg Chadwick top-scored with 50 as the hosts posted 186-9, opener Archie Graham adding 41 and Adam Morris 25no, loanee Dan Artley taking 3-53.
Craig Sanderson then smashed an undefeated 91 from just 77 balls as Filey sealed the win, hitting 10 fours and three sixes, Ryan Baldry scoring 37 vand David Brannan 26,
Brompton won by five wickets at home to Staxton.
Division Four champions Flamborough ended their season with a 23-run success at Forge Valley 2nds.
The visitors were in deep trouble early on until middle-order runs from Luke Dixon (35) and Harry Burton (39) steered them to 148, Charlie Ionascu taking 4-35 and Charlie Baldwin 3-13.
Valley skipper Steve Boyes (35) was the only Valley batsman to shine in reply, as they were dismissed for 125, Jack Carradice-Clarkson taking 3-25 for the victors.
Goathland ended their campaign on a winning note, triumphing by 14 runs at home to Wykeham 3rds.
The nine-man hosts were dismissed for 147, Charlie Parker hitting 49 and Liam Calvert 34 not out.
All-rounder Parker then scooped 3-16 as Wykeham were pegged back to 133-7, skipper Gary Owen hitting 38.