Jamaica's Usain Bolt, Yohan Blake, Nesta Carter, Michael Frater smashed the 4x100m world record
Usain Bolt's Jamaica smashed the 4x100m world record and Britain's Mo Farah clinched a magical distance double in a rousing climax to London Olympics track action.
Sprint legend Bolt anchored Jamaica's 36.84sec around the Olympic Stadium, which lowered their own mark set last year and pushed him out to a unique "double treble": the 100m, 200m and 4x100m titles, twice in a row.
Aided by Nesta Carter, Michael Frater and Yohan Blake, it put the seal on a glorious Games for the party-loving, 1.96m (six foot five) Bolt, who dominated the 100m and 200m without setting a new record.
"For me it's just great that we closed the show on a bang, that is what it meant to me," said Bolt. "I knew we could do it (world record) because the guys came out here, they were very hyped, they were ready, they were focused."
He celebrated by putting his fingers to his head in a copy of Farah's "Mo-bot" celebration -- a salute to the Somali-born Briton, who had electrified the crowd with his 5,000m win.
In a gripping race, swept along by a wave of noise at Olympic Stadium, Farah moved from the back of the field to the front and determinedly held off first Thomas Longosiwa and then Dejen Gebremeskel for victory.
Farah kissed the track and did sit-ups after the win, which after his 10,000m victory places him in the same category of distance greats as Emil Zatopek and Kenenisa Bekele.
"I got great support from the crowd," said Farah, whose wife is soon to give birth to twin girls.
"It means a lot to me and those two medals are obviously for my two girls who are coming. I didn't want to leave one out -- there's twins so it's one for each."
With Olympic Stadium now shuttered until Sunday's closing ceremony, and 15 titles available on the final day, the United States have a healthy lead on the medals table of 44 golds to China's 38. Third-placed Britain have 28.
The United States' flying women also had a huge win in the 4x400m relay -- a day after shattering the 4x100m world record -- and Russia's world champion Mariya Savinova held off South Africa's Caster Semenya in the 800m.
DeeDee Trotter, Allyson Felix, Francena McCorory and Sanya Richards-Ross brought home America's fifth straight victory in the relay, and a fourth win for their women's runners in London.
In the women's 800m final, Russia's Savinova made the decisive break coming round the bend to win her fifth successive major title. Semenya surged from fifth to second but ultimately left herself too much to do.
"I've been waiting all year for this," said Semenya, 21, who also won silver at last year's world championships but was barred from the track for almost a year, and had to undergo gender tests.
"The last four years have not been easy. I'm already thinking about Rio (2016 Olympic Games) and I hope I'll be there."
Trinidad and Tobago's Keshorn Walcott became the youngest ever Olympic javelin champion, at 19, with a throw of 84.58 metres.
With 32 gold medals handed out on the penultimate and busiest day, Mexico added to the drama when they shocked Brazil 2-1 in the men's football final, denying the five-time world champions the one major title to elude them.
David Boudia stunned Chinese favourite Qiu Bo in the men's platform diving as he became the first American winner since the great Greg Louganis in 1988. British favourite Tom Daly celebrated wildly as he took bronze.
The United States beat France 86-50 in the women's basketball final, extending a 41-game winning streak which stretches back to 1992.
Middleweight Ryota Murata won Japan's first boxing gold in 48 years, Briton Luke Campbell took out the bantamweight and China Zou Shiming retained his light flyweight title. Ukraine's Oleksandr Usyk was crowned heavyweight king.
Earlier, under hot sunshine in the British capital, home favourite Ed McKeever -- dubbed "Bolt in a boat" -- sped to victory in the men's single kayak sprint.
Russia's Sergey Kirdyapkin won the gruelling, 50km race walk in 3hr 35min 59sec, as several of his exhausted competitors collapsed on the finish line near Buckingham Palace. Russia's Yelena Lashmanova won the women's 20km walk.
Defending champions Germany won the men's hockey final 2-1 against the Netherlands, defending their title from 2008.