Mark Percival and Regan Grace both bagged braces as Saints beat Hull FC 38-12 to lift the League Leaders' Shield.
Saints wrapped up the trophy with two games to spare in a comfortable performance at the Totally Wicked Stadium.
Justin Holbrook’s side led 12-0 after 15 minutes – and then sealed victory in the second half.
Mark Percival crossed for his 23rd try of the season in the tenth minute when Jonny Lomax took a short pass, broke through and drew the full back.
Danny Richardson converted and within a couple of minutes he was adding on another after Morgan Knowles showed great strength to plough over.
But Hull FC drew level when Jordan Lane and Brad Fash scored to make it 12-12.
Saints hit back just before half time through Luke Thompson and extended their lead early in the second half with a Richardson penalty.
That eight-point gap gave Saints some breathing space against a committed Hull FC – and they then turned the screw.
Firstly, Percival’s second came after soft hands from James Bentley.
The debutant sent his centre away before Percy produced a dummy to fool the full back – and leave the whole of the Totally Wicked Stadium applauding.
Saints were rampant and on their next foray into the Hull 20 metre area Barba and Grace exchanged passes, twice, for the winger to cross.
Grace then added his second as he ran 60 metres from Percy’s pass and ducked under the full back for a superb try.
Jack Ashworth went close as the game came to an end but Saints had done more than enough to secure their 24th Super League win of the season.
Tries: Percival (2), Knowles, Thompson, Grace (2)
Goals: Richardson (7 from 7)
Tries: Lane, Fash
Goals: Faraimo (1 from 1), Connor (1 from 1)
Hull FC: 9
REF: C Kendall
23. Ben Barba; 2. Tommy Makinson, 30. Matty Costello, 4. Mark Percival, 19. Regan Grace; 1. Jonny Lomax, 18. Danny Richardson; 10. Kyle Amor, 15. Morgan Knowles, 16. Luke Thompson, 24. James Bentley, 21. Jack Ashworth, 12. Jon Wilkin.
Subs: 14. Luke Douglas, 20. Matty Lees, 22. Jake Spedding, 31. Jack Welsby.
28. Hakim Miloudi; 2. Bureta Faraimo, 30. Cameron Scott, 4. Josh Griffin, 5. Fetuli Talanoa; 35. Liam Harris, 14. Jake Connor; 29. Masimbaashe Matongo, 17. Danny Washbrook, 8. Scott Taylor, 11. Dean Hadley, 26. Jordan Lane, 21. Sika Manu.
Subs: 16. Jordan Abdul, 20. Brad Fash, 22. Jez Litten, 36. Lewis Bienek.