After an impressive third leg from Allyson Felix (49.64 — fastest of the day), USA Red’s Sanya Richards had a cakewalk to wrap up an eighth straight win for an American team in this series. The time: 3:23.08.

Novlene Williams-Mills gave it a great effort on Jamaica’s third leg, but ultimately could not match the impossibly smooth strides of Felix. The Jamaicans took second in 3:24.57.

Results.