Luke Jaques put them ahead but Cas levelled and it took a late winner from Sam Wright to bag full points.
Keeper Jordan Waddington and defensive duo Mitchell McHugh and Daniel Hall coped well, particularly in the first half.
Ferry won the second game 5-0, thanks to goals from Mason Gill (two), Wright (two) and Morgan Tucker.
Pontefract Social's Terriers were outclassed 7-0 at Rothwell under-eights.
Lewis Taylor worked hard at the back while midfielder Brandon Gill and keeper Craig Wilson shared the man of the match award for gritty displays.
Man of the match Joseph Smith got Tykes' consolation as Rothwell won the second game 13-1.
Sam Sanderson, Romaine Logan, Owen Thorpe and Alex Webb battled hard in defeat.
Ferrybridge under-sevens edged out Barugh Blue 1-0 in a keenly-fought tussle.
Man of the match Oliver Scales hit the deciding goal inside two minutes after good work from Joe Wilson and James Ford.
Luke Wilson, Josh Mosby and Declan Baker kept the back-line solid while Ford and Harry Blackburn went close in the second half.
A much-improved display could not prevent Ferry slipping to a 4-0 defeat in the return, despite excellent displays from Harry Jones, Declan Baker and Jacob Wright, who took a share of the match of the match award.
Striker Jae Priest was a constant menace.
St Joseph's went down 5-0 at Summer League rivals Upton in midweek.
Jed Nowells and Sam Burton shone in a bright start until Upton got their passing game together to open a 4-0 lead, which was tough on keeper Max Bland.
Joe's leaked only one more after a half-team reshuffle. The hard-working Ezra Pickles was man of the match, with Ben Freeman and Bland also catching the eye.
Upton won the return game 6-2, despite the impressive efforts of first-half keeper Herbie Hollis.
Dylan Masefield and man of the match Harry Thomas netted spot-kicks while second-half stopper Morgan Starks saved a last-minute penalty.
Kellingley Welfare under-sevens fightback came up short as they went down 4-2 at Ward Green.
They trailed 3-0 at the break but hit back with goals from Zak Bennett and Brandon Langton, who netted straight from a superbly-taken corner, to give the home side a scare.
Josh King and Langton worked tirelessly at the back and keeper Nathan Ruckledge made some excellent stops.
Kells' lost the return 5-0, despite hard-working displays from Jarrod Holmes, Tyler Robson-Tennant and Anton Cooling. Chloe Wakefield, Ellie Ruckledge and Jamie Greaves showed bags of promise.
Pontefract under-sevens thrashed South Kirkby Knights 8-1. Goals from Brad Evans and a long-range brace from Bradley Olbison made it 3-0 at the break and there was more of the same on the restart as Harry Kitchen, Harry Toole and Oliver Tait got on the scoresheet. Sonny Law and man of the match Matthew McConkey were impressive.
Goals from Kimberley Baxter, Tait and man of the match Ben Kitchen secured Ponte' a 4-1 win in the second game.