Adam Swift scored a brace as St Helens recorded an easy 21-8 win at Widnes Vikings in the Super League's Super 8s on Sunday.
St Helens were already assured of their place in the semi-finals, with Catalans Dragons unable to catch the 2014 champions in fourth place, and continued their fine form.
Swift crossed twice in the opening 10 minutes to put the visitors in front, although he later suffered a concussion, and St Helens controlled the match after racing into an early 10-0 lead.
Patrick Ah Van pulled one back for Widnes before half-time, but Matty Fleming's fifth try of the season restored St Helens' clear advantage, although Corey Thompson scored a consolation for Widnes.
Ah Van and Widnes skipper Kevin Brown were sent off after a brawl with just two minutes to go, with St Helens making the most of their advantage to score again in stoppage-time through Atelea Vea.
In the qualifiers, Huddersfield Giants bounced back from defeat at Leigh last time out to beat Leeds Rhinos 22-14 and boost their Super League survival hopes in the process.
Huddersfield are level on points with Hull KR, who eased to a 32-24 win at Featherstone Rovers as Josh Mantellato and Thomas Minns both scored braces, while Misi Taulapapa crossed twice in the last 10 minutes for the hosts - who will remain in the Championship next season.
In the final match of the season next weekend, Huddersfield and Hull KR face off, with a guaranteed place in next year's Super League up for grabs.