Jamaica's women's 4 x 100 meters relay team looked like the favorite entering Friday's final, with 100m gold medalist Shelly-Ann Fraser-Pryce and two-time bronze medalist Veronica Campbell-Brown running. And the Jamaicans did turn in the third-fastest time in history in the event. But Team USA's fleet foursome smashed the world record and left the Jamaicans in their dust for gold.
Tianna Madison, Allyson Felix, Bianca Knight, and Carmelita Jeter combined to run the final in 40.82 seconds, crushing the world record held by East Germany since 1985 by more than half a second, and thumping Jamaica (41.41) by almost six-tenths of a second.
The race, possibly the fastest in history, also featured Ukraine's four-woman team setting a national record at 42.04 seconds for bronze.
Felix's gold is the second of her Olympics. Jeter's gold gives her a medal of each color in London.