American sprinters won four of six races billed as ?The US vs. The World? at the Penn Relays, beating rival Jamaica to win both the men?s and women?s 4x100- and 4x400-meter relays. In the women?s 4x400, the United States team of Monica Hargrove, Natasha Hastings, Allyson Felix and Sanya Richards won in 3 minutes 23.08 seconds after Hastings lost her left shoe during the exchange with Hargrove and ran her entire leg with a bare foot.