Johnston tries to push off the cage with his feet but Walker rains down punches until he decides to take his left arm and successfully get the armbar just before the first round ends .
Walker then gets full mount and starts hurting Johnston with some elbows .
Johnston tries to push off the cage with Johnston 's feet but Walker rains down punches until Walker decides to take Walker 's left arm and successfully get the armbar just before the first round ends .
Walker then gets full mount and starts hurting Johnston with some elbows .