The hosts followed up their previous 3-1 win in Kent in the competition by scoring three first-half goals on their way to victory over Middlesex.
Lizzy Rose performed impressively in goal for the visitors and denied Cherelle Khassal when she went through one-on-one.
It may have just been coincidence but Middlesex – who had to make some late call-ups to their squad – seemed to be undone by repeatedly conceding quickly after making substitutions.
They lost Anya Kinnane to injury midway through the first half and weithin 4 minutes Khassal had provided a cross from which Sian Heather opened the scoring.
Moments after making a second change, Middlesex were 2-0 down as Sienna Howell played in Lauren Cheshire, whose cross found its way just inside the post.
With half-time approaching, a third sub came on afterwhich Cheshire picked out Kellie Larkin to fire in the third goal.
Cheshire was kept out from close range when Rose made a fantastic stop with her feet but she was not to be denied as when Heather delivered a lofted ball, it fell for her to hit on the volley into the top corner.
Photo – sussexfa.com