A header from Martha Thomas and an own goal by Hammers defender Grace Fisk put the Reds in the driving seat early on, before Leah Galton added a third strike just minutes after the second half had resumed.
Ella Toone and Alessia Russo both had opportunities to add to the scoring, as Marc Skinner's side comfortably returned to winning ways.
The Reds climb back into the top three with just one game remaining; we complete our WSL schedule this season with a trip to the capital to face Chelsea next Sunday.
FIRST HALF
Ona Batlle was the first to test West Ham's goalkeeper Mackenzie Arnold early on, as the Spanish international drove forward before her right-footed effort was well saved.