The greatest sprinter ever and the greatest swimmer ever stamped London as one of those rare Games to immortalise the deeds of not one but two athletes bound for the Olympic pantheon.
Usain Bolt and Michael Phelps created history of such enduring significance that their feats are likely to provoke wonder for as long as the Olympics exist.
What a headline double act for a Games that produced 44 world and 117 Olympic records.
Phelps is now statistically the most decorated Olympian of all time.
His haul defies belief - a record 22 medals, four more than Soviet gymnast of the 1950s and 60s Larisa Latynina, and 18 of them gold - twice as many as anyone else, including legendary names like Carl Lewis, Mark Spitz and Paavo Nurmi.
Phelps also became the only man to win the same swimming event three times in a row, and just to show it was no fluke he did it twice over - in the 200m individual medley and the 100m butterfly.
But is Phelps the "greatest" Olympian ever?
It's largely a pub argument, because most athletes don't get as many chances to win gold medals as, say, swimmers and gymnasts.
Putting medal lists to one side, which athlete announced himself as the global face of the Games? Many would say Bolt, the cool dude who even remembered to do up both of his laces this time.
The Jamaican was already the fastest man in history, and in London he became the first ever to pull off the "double double" - successive 100m and 200m sprint crowns.
How could anyone possibly supercede that? Do it three times?
That remains a possibility, as Bolt is still only 25.
But he has now satisfied his own definition of what it takes to become a "living legend" and whether his passion for elite running lasts another four years remains an unknown.
He went on to make it a "treble double", collecting his sixth gold medal when Jamaica's 100m relay team retained its Olympic crown, too, smashing its own world record in the process.
To hear that Bolt might not have produced the greatest single performance of the London track meet, however, gives some indication of how brilliantly Kenyan David Rudisha won the 800 metres.
He smashed his own world record in a display of power and pace which no less an authority than Sebastian Coe, former middle distance great and latterly London Games organising boss, rated the exploit of the whole Olympics.
As Phelps was departing the spotlight another American swimmer, 17-year-old Missy Franklin, was stepping into it, capturing four golds.
Chinese 16-year-old Ye Shiwen won the 200m and 400m medley golds in such devastating fashion that American coaches placed her in the suspicious category, something they failed to do when one of their own, 15-year-old Katie Ledecky, won the 800m freestyle.
It was a breakout Olympics for women, who fought for boxing medals for the first time. Another first came when Saudi Arabia, Qatar and Brunei sent female Olympians. Saudi judo fighter Wojdan Ali Seraj Abdulrahim Shahrkhani lost, in a headscarf and in less than 90 seconds, but she made a statement just by being in London.
In order to legitimise its own Olympics, London needed to produce plenty of host nation heroes. It did, to a degree few imagined.
Like Australia 12 years ago, the hosts bathed themselves in success. The land of hope became the land of glory.
Britain exceeded its wildest dreams by finishing third on the medals table behind the US and China with a staggering 29 golds.
It didn't get much better than Super Saturday, when Jessica Ennis, the face of London's Games, came up with the heptathlon gold her nation craved.
Cyclist Sir Chris Hoy won a record sixth gold medal to overtake rower Steve Redgrave, Mo Farah won the 10,000m and 5000m double, Tour de France hero Bradley Wiggins won the cycling time trial, Nicola "Babyface" Adams took the first ever women's Olympic boxing title ... the list went on and on.
Royalty got in on the medals act, too, when 14th in line to the throne Zara Phillips won an equestrian silver medal that was presented by her mum, Princess Anne.
Andy Murray finally won a title at Wimbledon, thrashing Roger Federer in straight sets on Centre Court a month after losing to him in the Wimbledon final. Would wonders never cease?
Not all of the headlines belonged to winners.
South African Oscar Pistorius, who was born without fibulas, made history as the first double amputee to compete with able-bodied athletes at the Olympics, running on carbon fibre supports that earned him the nickname the "blade runner".
Many people say they would run on a broken leg to appear in the Olympics, but American Manteo Mitchell actually did.
The 400m relay runner heard and felt his leg break halfway through his run, but kept going anyway "just like anyone would".
The Games were not without controversy. Eight badminton players were sent home in disgrace for trying to lose - doing it to gain a better draw in their tournament, but violating the Olympic spirit of competition.
Organisers scrambled to sell last-minute tickets, and ended up giving some to the military after unsightly photos of empty seats were splashed across the British press.
But London buzzed to universal delight, enthusing even the normally staid IOC president Jacques Rogge.
"For two weeks," he said, "the Olympic Park has been the beating heart of the world."