Interim head coach Mike Rush praised skipper Paul Wellens after St Helens bounced back from two defeats to hammer Castleford 44-12.
Rush said: "Wello was my star man. He scored a try and made another for Tommy Makinson with a long pass.
"He led from the front and told the players this week we need to end the season well."
Makinson, who retained his place when Ade Gardner was unfit to return after an eye injury, scored two tries including a length of the field effort after collecting a Richard Owen kick.
Rush added: "Tommy was excellent and sometimes young players need a kick up the backside and he did well.
"Defensively it was a lot better and we only conceded two tries. Their first frustrated me a little bit but overall I have to be happy."
Cas coach Millward said: "We were really competitive in the first half but our completion rate went down from 70% to 50%.
"Saints defended really well and I can't fault our effort and commitment. We had seven players out and three gone and we are not a big enough club to have that many players out.
"Four or five of their tries came from kicks. We went close a few times but their defence was too good.
"They are a top-three team and Saints played better than they have in recent weeks.