His place in history already secure, Usain Bolt added to his legend by anchoring Jamaica's 4x100-metre relay team to a world record and capping his second Olympics in a row with three gold medals.
After setting three world records in Beijing four years ago, the "NEW WR'' signal didn't flash up on the timing clock for Bolt until the last race on the track at the London Games, as he sped away from U.S. anchor Ryan Bailey to cross in 36.84 seconds. That shaved two-tenths of a second off Jamaica's old world mark.
After winning the 100 and 200 to anoint himself as a "living legend,'' he went full-throttle one last time at the games, gritting his teeth as his giant stride again made the difference.
This time he ran through and dipped at the line to get the world record and turn the U.S.-Jamaican men's sprint rivalry in the favour of the small Caribbean nation of 2.9 million.
Yohan Blake, Nesta Carter and Michael Frater set up the victory with in the first three legs that gave Bolt a platform to storm home down the final 100 metres.
It gave Blake the chance to experience Olympic gold after finishing second behind Bolt in the 100m and 200m finals.
"It's always a beautiful feeling to end off like this,'' Bolt said. "We did it last year in the world championships for me it is a wonderful feeling.''
The United States took silver in 37.04, equaling the old mark that Bolt and co. set last year at the world championships.
Trinidad & Tobago got the bronze medal when Canada was disqualified after finishing third.