The win sees the Ladies on to 120 points with one game to go and, despite the staggered nature of the remaining fixtures, they are now guaranteed a top two finish.
Phoebe Shelton's side are 18 points clear of second placed Banbury, who have a game in hand on Sileby, with Plumtree a further 17 points back.
Plumtree, like Sileby, have one game left, with the pair facing off against one another on 22 September with the league title on the line.
Promotion to the WML Premier is just reward for the hard work and improvement shown by the Ladies in recent years.
Good luck to the Ladies against Plumtree!