Castleford: (0) 4
St Helens: (36) 72
Tries: Wilkin, Talau, Wellens (2), Sculthorpe, Fa'asavalu, Lyon (2), Cayless, Roby, Long (2)
Goals: Lyon (12)
Castleford's relegation fears were increased as St Helens ran in six tries in each half at the Jungle, inflicting a club record defeat.
Paul Sculthorpe and Sean Long each bagged a brace, as did Jamie Lyon, who kicked all 12 goals.
John Wilkin, Willie Talau, Paul Wellens, Sculthorpe (2) and Maurie Fa'sasvalu scored in the first half.
James Roby, Jason Cayless, Long (2) and Lyon (2) completed the rout, with Gray Viane's late Cas try little comfort.
Castleford coach Terry Matteson:
"Saints are in good form but they don't need a hand from the referee.
"I'm not hiding our frailties but we've got a lot of kids out there and the harsh realities of Super League are taking their toll.
"I just don't understand why St Helens need a hand from the touch judges - it's really frustrating."
Saints coach Daniel Anderson:
"I can't stop the way we're playing and I asked at half-time if we could take it easy.
"But the players are in a mood and it's very difficult to stop them.
"I'd have to say that's one of the best performances I've been involved in and it's just good to come out of the game with no injuries."
Castleford: Platt, Bird, Shenton, Viane, A. Fletcher, McGoldrick, Handforth, Sculthorpe, Henderson, Nutley, Manu, R. Fletcher, Payne. Replacements: Kain, Edwards, Huby, Fa'aoso.
St Helens: Wellens, Gardner, Lyon, Talau, Meli, Pryce, Long, Cayless, Cunningham, P. Anderson, Sculthorpe, Wilkin, Hooper. Replacements: Fa'asavalu, Fozzard, Roby, V. Anderson.
Referee: K Kirkpatrick (Warrington)