Usain Bolt capped another incredible Olympics, winning his third gold medal by anchoring the Jamaican 4x100 relay team to a world record-breaking triumph.
The Jamaican team of Nesta Carter, Michael Frater, Yohan Blake and Bolt, going up against a formidable U.S. team, held their nerve in the final two legs, to smash the world record in a time of 36.84 seconds. The American quartet took silver in 37.04, equalling the previous world record.
Trinidad and Tobago won the bronze after Canada, who had crossed the line in third, were disqualified when Jared Connaughton was adjudged to have run outside his lane on the third leg.
With the win, Bolt defended all his three gold medals he won at the Beijing Games; asked if he would do it yet again in Rio in 2016, the 25-year-old said: "I've thought about it but I think it's going to be very hard because Yohan, he's just come into the game and he's running pretty well, and I'm sure there's going to be a lot more cats coming up to run.
"I'm just happy. I'll take it a step at a time."
The U.S. women's team, after creating a world record in the 4x100 relay, also took home the longer version the 4x400. The quartet of DeeDee Trotter, Allyson Felix, Francena McCorory and Sanya Richards-Ross dominated the race from start to finish, winning in 3:16.87, three-and-a-half seconds ahead of silver medallists Russia, with Jamaica taking the bronze.
Great Britain's Mo Farah completed a double, winning the 5000 meters in brilliant fashion.
Exactly seven days after winning the 10,000, Farah took advantage of a slow race to take the lead with nearly two laps remaining, comfortably holding off Ethiopia's Dejen Gebremeskel to win in 13:41.66. Thomas Longosiwa of Kenya took the bronze medal.
"It's an unbelievable feeling, the best feeling ever," an elated Farah said.
"Those two medals are to my two girls that are coming. They're twins so there's one for each. They could arrive any day."
Mariya Savinova of Russia took gold in the women's 800 meters, with former world champion Caster Semenya coming second.
Another Russian Anna Chicherova claimed the high jump gold, clearing a height of 2.05 meters. Brigetta Barrett of the U.S. won the silver medal while Svetlana Shkolina of Russia took bronze.
19-year-old Keshorn Walcott of Jamaica won a surprise gold in the men's javelin.