Usain Bolt seals place in World Championship history

Usain Bolt guided Jamaica to victory in the sprint relay in Moscow to become the most successful athlete in the history of the World Championships.
The 26-year-old added 4x100m gold to his 100m and 200m triumphs and now has a total of eight golds and two silvers.
Carl Lewis and Allyson Felix also have 10 medals but have eight golds, one silver and a bronze respectively.
Jamaica won in 37.36 seconds with the United States second and Canada third after Great Britain were disqualified.
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British relay team
Baton blunder cost Brits bronze
Britain finished third but lost their bronze after an appeal was lodged against their second changeover.
However, the women's relay team were later promoted to the bronze-medal position after France were disqualified for a similar infringement.
Bolt's latest triumph meant he joined Americans Michael Johnson, Felix and Lewis on a record-equalling eight world titles overall.
The 100m and 200m world record holder also secured a sprint triple in World Championships for the second time, matching the trebles he completed at the 2008 and 2012 Olympics.
"It is just great," Bolt said of the comparison. "I'll continue dominating. I'll continue to work hard. For me, my aim is to continue into the greatness thing."
The United States team gave the Jamaicans a scare but Rakieem Salaam's handover to Justin Gatlin left the individual 100m runner-up off balance.