Richards was named man of the match but he admitted the award should have gone to Muamba for anchoring the midfield.
"That was as good a performance as you'll see," coach Stuart Pearce said. "We wouldn't have won without him."
Richards added: "They found it very hard to break us down because of Fabrice.
"Credit to Theo (Walcott), when he came on he change the game and set up a goal."