Let's get that one moment out of the way: the moment Usain Bolt crossed the line.
The roar was deafening, the released tension was immense, and the entire stadium, it seemed, was ready to celebrate a dominant world record-holder winning from the unfamiliar position of underdog. The Jamaican section sang, Bolt hugged his parents, and Trayvon Bromell and Andre De Grasse tried to figure out which of them, if not both, was the bronze medallist. (The answer: both.)
But the competition sprawled over 13 hours and the men's 100m final was not the only memorable moment of day two. Here are six other bright moments that stick out from Sunday in the Bird's Nest.
A walk in the park
It wasn't strictly in the stadium, but the men's 20km race walk took place over a one-kilometre loop just outside. With Chinese race walkers poised to pick up medals, the drama was high, particularly as European champion Miguel Angel Lopez of Spain moved up on Zhen Wang's shoulder in the closing kilometre.
In the end Lopez, the bronze medallist from Moscow, improved to gold. Wang Zhen didn't get his gold, but did get the host country's second silver. And Benjamin Thorne walked a Canadian record to pick up an unexpected bronze. As race walks go, it was high theatre.
Heptathletes all day
There were three final events in the heptathlon, but two notable moments. There was the tense moments when Katerina Johnson-Thompson and a crowd of officials looked at the long jump board to decide if her third jump would be a foul like her first two.
And then there was the moment when Jessica Ennis-Hill stormed to the front of the 800m to cross the line first and then let all the emotion of the past two days wash over her.
The lead in the hammer final appeared to change with nearly every throw, and even the volunteer retrieving implements with a remote-controlled car was so enthralled he accidentally ploughed the car into the feet of the measuring official and knocked him over.
When Pawel Fajdek finally took charge with an 80.88m throw in the third round, the gold drama was over, but the lesser medals remained in play through the sixth round, when Wojciech Nowicki threw 78.55m, putting himself ahead of everyone but Fajdek and silver medallist Dilshod Nazarov.
One love, one shot
It was a great night for Jamaica in an entirely different event as well. O'Dayne Richards led the shot put from the third round to the fifth, his toss of 21.69m standing until first David Storl and then Joe Kovacs eventually surpassed him. The Kovacs-Storl rivalry went to Kovacs with 21.93m, but Richards' medal was an unexpected one for Jamaica.
The continuing saga of the Kenyan hurdlers
The potential Kenyan sweep in the 400m hurdles was slightly derailed when only two of the trio advanced to the final. But the big surprise in that event remains that a country previously best-known for middle and long distance runners is now a serious medal threat in the long hurdles.
The track is fast
The men's 400m qualifying justifiably provoked a few double-takes when Yousef Ahmed Masrahi of Saudi Arabia ran 43.93, an Asian record, in the second heat.
Behind him, Rusheen McDonald of Jamaica set a national record with the same clocking. None of the other heats were quite as brisk, but the ripple was already spreading.
Parker Morse for the IAAF