Leeds almost rescued a point in the final stages, recovering from 12-7 down at the start of the last period. But both teams were already guaranteed places in Championship 2 in the second half of the season.
English Roses also qualified thanks to a key 11-5 success against Birmingham, featuring six goals by Andrea Norris and three from Lou Betts.
Southampton revived their hopes as seven goals by Aimee Park ensured a 12-9 defeat of Sheffield Stingrays. At the bottom of the table, Sunderland collected a rare win - 9-7 against Polytechnic. The sides were level at 7-7 in the last quarter before goals by Ashley Boardman and Tamara Kaiser gave Sunderland the points.
Picture (Trevor Hyde): Molly Boniface-Ashton attempts another shot at Northampton.