Watch: Emotional Usain Bolt waves goodbye with another blistering gold medal
Usain Bolt knelt down to kiss the finish line goodbye as he greeted an emotional eighth Olympic title with a mixture of frustration and relief in Rio.
The Jamaican reacted with anger at failing to challenge his world record of 19.19 seconds as he raced to 200 metres gold in tough conditions.
He flew round the bend, but appeared to tie up down the home straight and finished in 19.78secs.
Canada's Andre de Grasse took silver in 20.02s, while France's Christophe Lemaitre edged out Great Britain's Adam Gemili for bronze in agonising fashion, with both men given the same time of 20.12.
Bolt was never in danger of being caught, but his anger at not going quicker was clear for all to see as he crossed the line and looked at the clock. He roared, disappointment etched on his face.
"I wanted to run a faster time," he said. "I knew it was going to be hard to break the record, but when I came out of the corner my legs decided, 'Listen, we're not going to go any faster'. I wasn't fully happy, but I'm happy that I got the gold medal."
He recovered to lap up the acclaim as he celebrated, draped in a Jamaican flag.
Bolt bent down to kiss the finish line in lane six, his lane, as he completed his lap of honour before performing his signature 'Lightning Bolt' pose, to huge cheers.
"I was just saying goodbye, this is my last individual event at the Olympics," he said. "In relays you never knows what happens, so I just wanted to say goodbye."
The three-time 100m and 200m champion is now just one 4x100m relay run away from his Olympic 'triple triple' - and, in his own words, sporting immortality.
"All I wanted to do was run the 200m and win an Olympic gold medal once, so to be an eight-time gold medallist now is a big deal," he said. "But I've worked hard and I've pushed myself to be the best.
"I've proven to the world you can do it clean. I've made the sport exciting, made people want to watch it, I've put the sport on a different level."
Ahead of the race he got the customary rapturous reception from the healthy crowd inside the Olympic Stadium and looked relaxed as always. He even managed a samba on the start line.
But the rain which began to fall around 20 minutes before the start of the race had put paid to any realistic chance of him threatening his world record.
And in the end he could not get near it, with his time his slowest of any of his seven global 200m winning marks.
There remain, however, fewer better sights in sport than the world's fastest man in full flight.
Bolt, who celebrates his 30th birthday on Sunday, admitted that this run might have been his final 200m at a major championships. His plan currently looks set to be to compete in the 100m and relay at next year's World Championships in London, his last before retirement.
"I know when I go home and think about it I will probably get a bit emotional," he said. The 200m is after all his favourite event. It is the one he raced as a junior and the bond remains strong.
This could be, then, the end of an era for Bolt and world sprinting.
Asked how he wanted to be remembered, he replied simply: "Just as one of the greatest."
When he does bow out for good next year Bolt will leave an almighty void to fill. Indeed, the task of how to replace the Jamaican when he is gone is one of the toughest challenges facing the sport.
And, at 21, De Grasse looks best placed to inherit Bolt's mantle, in terms of being the world's leading sprinter if not the all-around showman and record breaker.
Asked if he would be happy to see the back of Bolt or wanted him to continue, De Grasse said: "A little bit of both. I love competing against him, it's an honour to be a part of history, of what he's accomplished in his career. If his time is up I guess a new person has to come in."
Victory means Bolt is now just one race away from a clean sweep of nine sprint golds across three Games.
His Jamaica team races in the final of the 4x100m on Friday night after they eased through Thursday's heats without their main man, Britain's team also squeezing into the final.
"I just really want this one to make it nine, because I like them in threes," said Bolt.
Shortly before Bolt claimed his latest gold medal, Ashton Eaton became the first man since Daley Thompson to retain an Olympic decathlon crown.
"It has been a pleasure being in same era as Usain Bolt," the American said. "The guy's last name is Bolt and he's the fastest man ever, you can't write stories like that."