St Helens talisman Lachlan Coote produced a full-back masterclass to help book a derby Grand Final with rivals Wigan.
Coote scored two tries, had a hand in two others and kicked eight goals as the champions shrugged off the physical challenge of the Dragons to seal their trip to Hull on Friday.
Catalans were already missing the suspended Micky McIlorum and Joel Tomkins and had James Maloney and Ben Garcia sin binned during an often feisty clash.
Saints veteran James Graham’s hopes of a fairytale finish to his outstanding career also hinge on him passing the sport’s concussion protocols this week after he failed a head injury assessment.
Fellow forward Louie McCarthy-Scarsbrook was initially reported – incorrectly – to have failed a head test as well, but returned to the field in the second half.
And with James Roby typically immersed in the action throughout and Kevin Naiqama scoring a terrific hat-trick, Kristian Woolf’s side had too much for a Dragons team that fell one hurdle short of its maiden Grand Final.
Saints led 14-2 after an often brutal first half that included a host of high tackles.
One of them saw Maloney – who had opened the scoring with an early penalty – shown a yellow card in the opening stages.
The home side capitalised with eight points in his absence.
Roby showed all his experience to attack the blindside from dummy half with most of Saints’ attack lined up the opposite way, and Coote crashed over from close range.
The full-back added a conversion and penalty, before Saints extended their lead on the half-hour mark with a brilliant try.
Smart handling to the right released winger Tommy Makinson on halfway, and when he escaped the covering Josh Drinkwater, Kevin Naiqama supported to score.
The Dragons blew a chance to respond right on half-time when Tom Davies knocked on in sight of the line, and Naiqama’s second shortly after the restart effectively ended the contest.
The Fijian centre touched down after kicks from Theo Fages and Coote, who then stepped up his contribution further.
The Aussie took a sublime inside flick pass from Zeb Taia for his second try, and was then involved in the build-up for another slick try for Jonny Lomax, extending the lead to 28 points.
Further tries from James Bentley and length of the field breakaways by Naqaima and Regan Grace completed the scoring – now Wigan await.