Hull's under-strength side produced a valiant effort to ensure there was no Wembley hangover but it was not enough to prevent St Helens securing a 31-10 win.
Winger Jack Owens scored 18 points with two tries and five goals as Saints took another significant step towards clinching a semi-final spot despite being well below their best.
With an eye on bigger games to come in the Super 8s, coach Lee Radford rang the changes for the Super League leaders, bringing in Leon Pryce, Jordan Abdull, Jack Downs, Iafeta Paleaaesina and Curtis Naughton as well as Jordan Thompson and Dean Hadley, the two players left out of his 19-man squad at Wembley.
Big guns Gareth Ellis, Danny Houghton, Marc Sneyd, Carlos Tuimavave, Mark Minichiello, Scott Taylor and Kirk Yeaman were all rested and Hull lost one of their Wembley heroes, winger Steve Michaels, after 12 minutes with a head injury sustained while running the ball out of his own in-goal area, although he was able to return later in the game.
But, led by former St Helens favourite Pryce on potentially his final appearance in Super League, the Black and Whites looked anything but a weakened team as they bossed the game for long periods.
Hull did the double over Saints in the regular season as well as knocking them out of the Challenge Cup on their way to Wembley and they were on course for a fifth successive win at Langtree Park after dominating the opening quarter.
Centre Mahe Fonua caught Saints defenders napping at a play-the-ball close to their line by dummying his way around the blindside of the ruck and tip-toeing his way over for the game's first try.
Saints struggled badly in the absence of suspended experienced playmaker Luke Walsh but full-back Jonny Lomax came up with two acts of class to get Owens and centre Matty Fleming over for two quick-fire tries early in the second quarter to edge them in front.
Owens added one conversion to make it 10-6, which was the half-time score as the home side struggled to get their game together.
They were livelier in the second half but could never pull clear of their gritty opponents.
A break through the heart of the Hull defence by scrum-half Theo Fages set up the position for substitute Atelea Vea to take Jordan Turner's pass and crash through the attempted tackle of Danny Washbrook and Chris Green for Saints' second try.
Owens' second conversion made it 16-6 but St Helens conceded a drop-out by failing to secure the restart and second rower Sika Manu pulled a try back for Hull, shrugging off the challenge of Dominique Peyroux to gallop over.
When Hull prop Liam Watts was harshly adjudged to have stolen the ball illegally, Saints took the chance to re-establish a two-score lead with an Owens penalty but it was a tenuous one.
St Helens were indebted to winger Adam Swift, who marked his 100th appearance with a brilliant try-saving tackle to deny Michaels on 66 minutes and then took play to the other end of the field with a break out of defence to create the position for the winning try.
That went to Vea who was the first to reach James Roby's grubber kick to record his second try and Owens kicked his fourth goal.
Turner then made sure of the win with a drop goal before Owens rounded off the scoring four minutes from the end by converting his second try.