After being put into bat at Savile Park by home side skipper David Wainwright, Duncan Brown and Prince Bedi started positively putting on 52 for the first wicket in 10 overs before Bedi fell for 20.
Breidyn Schaper added 23 but a mini collapse saw the away side slip to 109-4. Brown was in majestic form, reaching his fourth half-century of the campaign from 54 balls.
Hayden Williamson chipped in with valuable support to keep Brown company but the opener finally fell for a superb 87 (122 balls, 11x4 1x6) to leave Scarborough 160-7 as they struggled to contain the host's spinner Eddie Morrison who claimed 5-49.
In-form Linden Gray responded well and the all-rounder hit a 27-ball 28 to steer Scarborough to a final total of 202-9.
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An early Guy Emmett strike gave the visitors confidence and after Linden Gray (2-30) bagged a quick double, the home side had dropped to 60-3.
But, Chris Briggs proved to the the rock of the reply. The number three batted with great poise and patience to add 48 runs for the fourth wicket with Jack Young who made 24 before falling to Adam Newington.
Liam Hyde then joined Briggs and through intelligent batting, the pair put on an unbroken stand of 99 to ease home with 17 balls to spare.
Briggs ending on a superb 78no from 143 balls and Hyde undefeated with a 47 ball 53.
Scarborough face a double header next weekend with both Sessay and Woodhouse Grange visiting North Marine Road as they hope to return to winning ways.
*Castleford 207-4 (Chris Briggs 78*, Liam Hyde 53*, Jack Young 24, Linden Gray 2-30) beat Scarborough 202-9 (Duncan Brown 87, Linden Gray 28, Breidyn Schaper 23, Eddie Morrison 5-49) by 6 wkts