The United States won the women's 4x100m relay in world record time on Friday evening, completing the lap in a sizzling 40.82 seconds.
It is the first time Team USA have won the race since 1996.
Bungled handovers had denied the Americans gold at the last three Games but Tianna Madison, Allyson Felix, Bianca Knight and Carmelita Jeter combined slickly to beat the world mark of 41.37 set by East Germany in 1985.
Shelly-Ann Fraser-Pryce, Sherone Simpson, Veronica Campbell-Brown and Kerron Stewart won silver for Jamaica in 41.41.
Olesya Povh, Hrystyna Stuy, Mariya Ryemyen and Elizaveta Bryzgina combined to finish third for Ukraine and claim bronze.