In what turned out to be a cagey affair at Leigh Sports Village, the Reds battled hard during the first 45 minutes but couldn't score. Ella Toone enjoyed the game's best chance early on, but, on a landmark 100th appearance, was denied by Brighton & Hove Albion goalkeeper Katie Startup.
Marc Skinner's side were thus made to wait during the encounter but eventually broke the deadline after 68 minutes. Leah Galton latched onto a clever pass from Toone and duly finished past Startup.
Victory keeps United in third place in the Women's Super League. The Reds are three points ahead of rivals City, who have one game-in-hand and a slightly inferior goal difference.