If there were any doubts, it took less than 10 seconds - 9.81, to be exact - for Usain Bolt to erase them.
He is the Olympic champion once again.
On a muggy Sunday night in Rio, the Jamaican superstar won the signature event in track and field in a runaway and added this line to his already gleaming resume: first person to capture three straight 100-metre titles at the Olympics.
The 6-foot-5 sprinter overcame his typically slow unfurling from the blocks, gradually worked up speed, caught American Justin Gatlin with 40 metres left and was celebrating - pointing at his chest with his thumb - before he crossed the finish line.
Bolt beat Gatlin, who was greeted by the fans with raucous boos, by .08 seconds. Andre de Grasse of Canada won the bronze.
Chants of "Bolt, Bolt, Bolt" rang out from the near-capacity stadium. The show lived up to its billing.
No, this wasn't Bolt at his fastest - or even his best. The man who burst onto the scene with his hot-dogging world record eight years ago in Beijing turns 30 after these Olympics and says these will be his last.
"I am a living legend," he said. "Somebody said if I win these three gold medals I would be immortal and I kind of liked it. So I'm going to run with that one.
"I'm happy and I'm proud of myself. It wasn't perfect execution, but I'm proud of myself. I wanted to set myself apart from everybody else and this is the Olympics, I have to do it.
"I came to this Olympics to win three gold medals, to prove myself again as one of the greats."
More from Bolt
Unsurprisingly, the sprint king kept himself busy with the media after his 100m victory. Some more quotes are coming through now - here's what he had to say:
"I am a living legend. Somebody said if I win these three gold medals I would be immortal and I kind of liked it. So I'm going to run with that one.
"I'm happy and I'm proud of myself. It wasn't perfect execution, but I'm proud of myself.
"I wanted to set myself apart from everybody else and this is the Olympics, I have to do it.
"I came to this Olympics to win three gold medals, to prove myself again as one of the greats."
Van Niekerk's magical night
Wayde van Niekerk pulled off one of the most spectacular pieces of sprinting in history on Sunday night, breaking Michael Johnson’s long-standing 400m world record to win the Olympic title in breathtaking fashion.
Read our athletics correspondent Ben Bloom's report here.
Gatlin booed by Rio crowd
Justin Gatlin was booed as he entered the Olympic Stadium to face Usain Bolt in the 100 metres final.
Usain Bolt said after the race the crowd treatment of Gatlin had been "shocking".
Social media reaction
If there were any doubts, it took Usain Bolt 9.81 seconds to prove he is still the fastest man in the world.
Then it took him about five minutes to take to social media and dedicate the win to "his people."
Read more here.
"Immortal"
More from Bolt here: "It was brilliant. I didn't go so fast but I'm so happy I won. I told you guys I was going to do it.
"Somebody said I can become immortal. Two more medals to go and I can sign off. Immortal."
He added that "the 200m will be the sweetest one".
Reaction from Van Niekerk to his new 400m world record
"I believed I could get the world record," Van Niekerk said. "I've dreamed of this medal since forever. I am blessed."
Kirani James, meanwhile, said: "I'm happy to be part of a race that made history. We have put this sport on a pedestal."
Highlights of the night
Bolt speaks
"It was brilliant. I am really happy, though I expected to go faster.
"I am just happy that I won and that's the key thing."
On Gatlin being booed:
"I was surprised - it was the first time I have ever come into a stadium and they actually booed somebody... but for me I didn't care about that."
And there's the pose
The difference
Gatlin strains everything for the finish... Bolt crosses the line by thumping his chest.
