Britain's Mo Farah became only the second man to retain both Olympic track long distance titles on Saturday, when he produced an utterly dominant performance to add the 5,000 metres gold to the 10,000m he collected a week ago.
Farah followed Finland's Lasse Viren, who won both titles in 1972 and 1976, and having also done the double twice at the world championships, he has now earned his place among the all-time greats of his sport.
Farah dealt with everything the field could throw at him on Saturday, and even took up the pace midway through the race to stamp his authority on the field.
As ever, when it came to a last-lap showdown, nobody could live with his speed and he surged clear of Kenyan-born American Paul Chelimo and Ethiopian Hagos Gebrhiwet.
Things were never going to be easy for Farah as Ethiopian trio Dejen Gebremeskel, Muktar Edris and Gebrhiwet all passed up the 10,000m to concentrate on the shorter distance, and all three boasted faster personal bests than Farah.
After so many races where the rest of the field played into his hands by going steadily and opening the door for a last-lap burn-up, Farah was initially presented with a different challenge as Gebremeskel and Gebrhiwet set off at a hot pace from the start.
However, by the halfway point they seemed to have given up on that approach and Farah moved to the front to push the pace, and as it reached the final lap, he was, as always, unbeatable.
"I can't believe it. My legs were a bit tired after the 10k, I don't now how I recovered," he told reporters. "It shows I didn't just fluke it in London, to do it again is incredible. I just want to see my kids and hang this medal around their necks."
"I was surprised by the first lap, I thought it was going to be a slow race. They had a plan, they wanted to take the sting out of me but when I hit the front, I wasn't letting anyone past me," he said.
Meanwhile, American runner Matt Centrowitz scored an upset win to claim gold in the 1,500m. Centrowitz produced the biggest upset on the final night of track competition, relegating defending champion Taoufik Makhloufi of Algeria to second place, and win gold in 3min 50.00sec.
Centrowitz became the first American man in more than a century to win the event, which has been shared exclusively between African runners since 1996. The last American to win the 1500m in the Olympics was Mel Sheppard in the 1908 London Games.
"There's nothing like it. It doesn't compare to anything else I've won in my life," said Centrowitz. "Doing my victory lap, I literally kept screaming to everyone I know, 'Are you kidding me?'"
New Zealand's Nicholas Willis took the bronze medal in 3:50.24. Centrowitz's win was one of three golds won by the United States, who also took both the 4x400m relays.