The USA's women's 4x100m relay team win gold at the London Olympics, setting a new world record in the process.
The USA's women's 4x100m relay team set a new world record in winning the Olympic final in London this evening.
Tianna Madison got the Americans off to a positive start by accelerating out of the blocks. By the time she had reached Allyson Felix, the USA were already in the lead.
Felix exchanged the baton cleanly with Bianca Knight, who in turn released Carmelita Jeter down the home straight.
Jeter powered through the remaining 100m to cross the line in a time of 40.82s, which has broken the previous world record that had been held by East Germany since 1985.
The Jamaican squad, which included Shelly-Ann Fraser-Pryce and Veronica Campbell, set a new national record time of 41.41s on their way to clinching the silver medal.
Ukraine also produced a national record, finishing in 42.04s to take bronze.
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