Harlequins have secured a home semi-final in the Premier 15s after a comprehensive 67-0 win over basement side DMP Durham Sharks.
Quins led 36-0 at half-time, thanks to a hat-trick from returning England Six Nations winner Jess Breach, and controlled matters after that.
They will face Wasps in the semi-finals on Saturday 22 May while Saracens take on Loughborough Lightning.
Wasps, who could have overtaken Quins for second, beat Bristol Bears 62-12.
Katie Mason crossed for a hat-trick while there were two tries apiece for Ellie Kildunne and captain Katie Alder.
Saracens consolidated their place at the top of the table with a 27-0 bonus-point win over Worcester Warriors.
Marlie Packer, back in the side after international duty with England, scored her 40th try in the competition while Zoe Harrison kicked a penalty in a tight first half.
But Georgie Lingham, Kat Evans and Rachel Laqeretabua secured the victory in the second half.
Loughborough also finished their regular season on a winning note, beating Sale Sharks 26-12.
In the final game of the day, Gloucester-Hartpury rallied in the second half to defeat Exeter Chiefs 18-12.