In a tight and tense affair at Leigh Sports Village, two quickfire second-half goals from Reading strikers Natasha Harding and Danielle Carter settled the game.
The result leaves the Reds second in the table after 14 games, although third-placed Manchester City could make up ground later this afternoon when they face Arsenal.
MATCH DETAILS:
United: Earps; Thorisdottir, A.Turner, M.Turner, Batlle; Ladd (Groenen 54), Zelem (c) (Fuso 87); Hanson (Sigsworth 57), Toone, Galton; Press.
Substitutes not used: Bentley, Harris, Bourne, Jones, Ross.
Booked: Sigsworth.
Reading: Mitchell, Cooper, Bartrip, Woodham; Eikeland, Fishlock, James, Rowe; Harding, Carter (Harries 67).