Castleford Tigers Women have confirmed the League Leaders Shield, having won 13 out of 13 so far this season.
They clinched it with a 44-0 win over York City Knights at the Mend-A-Hose Jungle.
A hat trick from Rhiannon Marshall, two tries each for Tara Stanley and Lacey Owen and another from Millie Walsh and Tamzin Renouf claimed the win for the Tigers.
That result now means they are guaranteed a home semi final against Wigan Warriors in the playoffs.
Their attention now switches to their game against second placed St Helens, a team looking to defend their unbeaten home record and avenge their only defeat of the season.
As for York, they remain second bottom but do have one game in hand, against third bottom Featherstone Rovers, which they will play on Sunday at the LD Nutrition Stadium.