Saints maintained their dominance over Wigan with a third victory against the 2018 women's champions in as many derbies this season.
Telegraph Woman of Steel nominee Emily Rudge scored two of the five tries in a 28-0 win at the Totally Wicked Stadium, which also secured second place in the final Betfred Women’s Super League table.
Rudge crossed twice in the first half with Faye Gaskin converting both to give the hosts a 12-0 lead.
Rhianna Burke added a third before Tara Jones scored an excellent individual try through the middle and Chantelle Crowl completed the emphatic victory with a dart from close range just before full-time.
Saints are now guaranteed home advantage in the first round of the top four play-offs against Leeds Rhinos, who recorded a comprehensive win over bottom side Wakefield Trinity at the Mobile Rocket Stadium.
The round will be completed on Tuesday night, when Castleford Tigers are hoping for another bumper crowd at the Mend-a-Hose Jungle as they host York City Knights, needing a win to secure the League Leaders’ Shield.