Tigers coach Daryl Powell chose to rest some of his frontline players against St Helens after the excesses of two games in four days last weekend and his fringe prospects proved equal to the task in a 16-12 victory at The Jungle.
First-half tries from Mark Percival and Louie McCarthy-Scarsbrook had the Saints 12-4 up at the interval and on the way to completing a double over the Tigers.
But the hosts clocked up 12 unanswered points in the second period to edge a testing encounter, with Mike McMeeken and Tom Holmes touching down.
72: TRY CAS!!! Holmes chases back on the inside from Minikin's kick and touches down. pic.twitter.com/8c885vGPCE
— Castleford Tigers (@CTRLFC) June 4, 2017
That came after Salford had succumbed to a 34-24 home loss against Wakefield, who made it six league wins in a row.
Chris Chester's men impressively shrugged off the disappointment of this week's triple injury blow which saw Jacob Miller (broken leg), Adam Walker (medial ligament) and Tinirau Arona (hamstring) ruled out for several weeks.
The visitors started and finished strongly, racing into a 16-0 lead and, having been pegged back, scored two converted tries in the final four minutes through hat-trick hero Mason Caton-Brown and James Batchelor.
Warrington Wolves suffered another thrashing to leave coach Tony Smith facing more difficult questions, his side going down 44-4 at Huddersfield Giants to follow a 40-0 reverse at Leeds Rhinos and a 38-12 defeat at the hands of Salford.
Elsewhere, Widnes Vikings climbed off the foot of the table with a second win on the bounce, as Catalans Dragons were beaten 26-6.