St Helens wing Ade Gardner claimed a fine hat-trick as his side cruised into the Challenge Cup semi-finals.
St Helens (20) 56
Tries: Long, Gardner 3, P Anderson 2, Wilkin, Pryce, Lyon, V Anderson
Goals: Lyon 8
Catalans (6) 10
Tries: Jones, Murphy
Saints were made to work hard early on and Stacey Jones' converted try put Catalans 6-4 ahead after 17 minutes.
But St Helens took control before half-time thanks to two tries from Gardner and one from Paul Anderson.
And it was one-way traffic after the break as Saints scored another six tries, with Gardner scoring his third, while Jamie Lyon scored 20 points.
Lyon crossed for a try in the second half and also kicked eight conversions.
Saints, the Super League leaders with just one defeat in 15 games, have now reached the semi-finals of the Challenge Cup for the sixth successive year.
And although they went behind early on, two tries in the final four minutes of the opening half sealed Catalans' fate.
The French side did score a memorable consolation try in the second half however, when wing Justin Murphy sprinted in from 90 metres.
St Helens coach Daniel Anderson:
"I'd say it was mission accomplished. We're through to the last four.
"It won't be in the archives as one of the better games. I was disappointed with the first half. There were a lot of stoppages and injuries. It took forever to finish.
"The wind played a bit of havoc with our passing and kicking but, in the end, our front rowers produced enough impetus and created enough opportunities to enable us to score the points."
Catalans coach Mick Potter:
"The scoreline was disappointing. They had a lot of possession and we turned the ball over.
"You can't give a team like St Helens that amount of possession and compete.
"They're a quality side. Since I've been here, they have been the stand-out team and they probably will be in for the double."
St Helens: Wellens, Gardner, Lyon, Talau, Meli, Pryce, Long, Cayless, Cunningham, P Anderson, Gilmour, Sculthorpe, Hooper.
Replacements: V Anderson, Wilkin, Fa'asavalu, Graham.
Catalans: Guigue, Murphy, Wilson, Hughes, Verges, Frayssinous, Jones, Fellous, Rinaldi, Guisset, Jampy, Fakir, Hindmarsh.
Replacements: Chan, Beattie, Berthezene, Rudder.
Referee: R Silverwood (Dewsbury).