Of the six games they have now won this season, half have come against Catalans Dragons.
However, they have never had to work as hard as they did last night to see off the competition's struggling bottom club.
Castleford ended their three-match losing run with a crucial success to re-ignite their play-off hopes, moving back up to 10th after under-rated winger Michael Wainwright scored two vital tries.
But it came at a price with England centre Michael Shenton – who had scored twice himself against France on Saturday – being carried off with a knee injury in the final seconds.
"It doesn't look good," admitted coach Terry Matterson. "We don't know how bad it is yet but he's a tough guy and doesn't stay down so it doesn't look very promising. It made for a pretty nervy last minute as well as we were down to 12 men with no interchanges but we got there.
"Catalans played some good rugby considering they had a lot backing up from the Test match and we had to dig in."
Determined Catalans, who have won just twice all season and had ex-Castleford scrum-half Brent Sherwin lining up after last month's surprise switch to Perpignan, fielded 10 men who had been thrashed by England just three days earlier.
They started well, though, former Brisbane Broncos hooker Casey McGuire, back after a month out with a calf injury, instantly making his presence felt as he wriggled over.
Castleford had an instant opportunity to respond but, after Dean Widders's last-tackle defence-splitting pass had sent Stuart Jones clear down the left, the erring second-row, with support on his inside, panicked and aimlessly flung a pass in the opposite direction straight to Catalans winger Frederic Vaccari. They had other opportunities just like it.
Matterson's decision to send Steve Snitch into the fray on the 19th minute proved crucial as the second-row, returning after missing last week's loss against Wigan, scored with his first touch.
Catalans' ill-discipline allowed the hosts to apply some pressure and they finally cracked when Rangi Chase's well-timed inside pass ushered Snitch in between the posts for Joe Westerman to convert.
Castleford captain Ryan Hudson spilled over the line after making a dart from dummy-half but former Huddersfield forward Snitch was in again in the 27th minute courtesy of the same combination.
Chase's bruising tackle forced a Catalans error and the effervescent scrum-half's short pass put Snitch over for his second, doubling his tally for the campaign.
Westerman improved once more to make it 12-4 and Castleford, growing in confidence after some early nerves, seemed set to push on against their jaded opponents.
However, as has been their downfall all season, Matterson's men crucially switched off to gift Catalans a way back in.
Young full-back Jordan Thompson spilled Sherwin's steepling kick and, although they defended their line well – Wainwright coming in off his wing to dislodge the ball as Cyril Gossard headed close – Mitchell Sargent cheaply lost possession, again trying to off-load on his own 20-metre line.
They then conceded a dubious penalty to invite more pressure and eventually Widders was too easily shrugged aside by Sebastian Raguin, William Barthau's conversion leaving them trailing just 12-10 at the break.
Castleford dominated the start of the second period but were stunned when Kevin Walters's side broke away to score through Vaccari in the 53rd minute, the winger profiting off Sherwin's long cut-out ball after Shenton had initially denied the surging Dane Carlaw.
Barthau kicked from the sideline and Catalans should have extended their lead when Dallas Johnson marauded down centre field but the ex-Melbourne star ignored his support and was locked up by Thompson.
Moments later, Castleford regained the initiative when Chase's skewed kick fortuitously found Wainwright who turned and found a clear path to the line, Westerman adding his third conversion.
Shenton and Kirk Dixon denied Raguin with a combined tackle but it was Castleford – whose improved kick-chase saw them force two drop-outs – who would finally take a hold.
Sargent went close following good approach work from the lively Kyle Wood, the youngster brought in on loan from Huddersfield as Sherwin's replacement, before Wainwright eased nerves by applying an expert finish after supporting Snitch's break down the left.
Vaccari slid over in the closing stages, while Shenton was down in back play, but Castleford held on.
Castleford: Thompson; Dixon, Shenton, Ferris, Wainwright; Widders, Chase; Jackson, Hudson, Higgins, Huby, Jones, Westerman. Substitutes: Snitch, Wood, Arundel, Sargent.
Catalans: Barthau; Bell, Raguin, Gossard, Vaccari; Sa, Sherwin; Ferriol, McGuire, Guisset, Elima, Carlaw, Johnson. Substitutes: Mounis, Fakir, Casty, A Bentley.
Referee: Richard Silverwood (Mirfield)