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.
"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."
Bolt's charisma and freakish ability has won him legions of fans not just in his native Jamaica, but throughout the world. Sometimes, the reaction to his wins can be as exciting as the event itself.
In this first video, the Jamaican Star shows the reaction of home fans to the gold medal. Our favourite is the man signing the superhero/lightning bolt song at the 2.47 mark. It's really worth a watch.
Will Bolt do the triple triple?
Thoughts are now turning to whether Bolt can once again score a treble at the Olympics. In the 2008 and 2012 Games the Jamaican swept the 100m, 200m and 4x100m relay.
What do you think? Can he possibly do it again?
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."
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".
4:25am
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."
3:25am
"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".
telegraph.co.uk