The 100 metre world recorder Usain Bolt banged in another gold in a competitive finals that saw his country man, Blake finish fourth.
Bolt only needed 9.57 seconds to break his own record and set another but fell short by 02.23 seconds and emerged the top after 9.81 seconds, 0.05 seconds faster than his recorded finishing time during semifinals of 9.86 seconds.
Bolt, 29, replicated his success at Beijing 2008 and London 2012. Gatlin who was twice banned for doping offences finished 0.08 seconds behind Bolt to take silver.
Canada’s Andre de Grasse took bronze in a personal best of 9.91, ahead of Bolt’s Jamaican team-mate Yohan Blake.
“Somebody said I can become immortal. Two more medals to go and I can sign off. Immortal,” said Bolt.
“It wasn’t perfect today but I got it done and I’m pretty proud of what I’ve achieved – nobody else has done it or even attempted it,” he added.
“I expected to go faster, but I’m happy that I won. I did what I had to.”
Bolt received a hero’s reception as he walked out into Rio’s Olympic Stadium before the race, and the crowd chanted his name after his victory.
The world record holder, who said in February he would retire from athletics after the 2017 World Championships, competes in qualifying for the men’s 200 on Tuesday, with the 4x100m relay beginning on Friday
“After the semi-final I felt extremely good,” Bolt added.
“I wanted to run faster but with the turnaround time, we normally have two hours, but we had one hour 20 minutes, it was challenging.
“This is what we train for. I told you guys I was going to do it. Stay tuned, two more to go.”