Saints suffered their third Super League loss, after a 28-14 defeat at the hands of Castleford
Castleford went over first through Peter Mata’utia, after he collected a ball from Danny Richardson to power over, with Richardson able to convert.
Derrell Olpherts, denied due to obstruction earlier, crossed on his second attempt after he defied physics in the corner.
Matty Lees saw yellow for a high shot on Jordan Rankin, allowing Olpherts to contribute his second score of the afternoon.
Saints did hit back before the break, with Tommy Makinson sprinting his way down the wing to score, but the conversion was missed.
HT: Castleford 14-4 Saints
An ill-disciplined St Helens received a second sin-bin as Louie McCarthy-Scarsbrook was sent for a temporary dismissal, but their defence held firm.
The Tigers further extended their lead via Cheyse Blair, as he caught a loose ball to smartly finish, with Richardson later adding two penalties.
Jack Welsby hit back with seven minutes remaining, but this was cancelled out imminently by Trueman, as he leapt onto a loose ball.
Luke Thompson did score a consolation in the closing stages, after Alex Walmsley broke through the line.
FT: Castleford 28-14 Saints
Tigers: Rankin, Olpherts, Mata’utia, Shenton, Clare, Trueman, Richardson, Watts, McShane, Griffin, Blair, McMeeken, Massey; Subs: Millington, Milner, Sene-Lefao, Smith
Vikings: Coote, Makinson, Naiqama, Welsby, Grace, Lomax, Fages, Walmsley, Roby, Thompson, Taia, Peyroux, Knowles; Subs: McCarthy-Scarsbrook, Lees, Amor, Smith