Not even a heavy pitch at The Dripping Pan ground, affected by adverse weather and the staging of a men's fixture 24 hours earlier, could prevent Casey Stoney's side creating numerous chances.
Katie Zelem forced the first notable parry by Lewes goalkeeper Faye Baker in the 14th minute, after some positive link-up play between United captain Alex Greenwood and Mollie Green on the right. Millie Turner was unfortunate not to convert the rebound, instead striking the outside of the left-hand post from close range.
Baker also made some fine stops following two Zelem corners, to keep out a shot from Greenwood and then to tip the ball over the bar when the next set piece threatened to go directly in.