Usain Bolt has described his World Championships 100m final victory over Justin Gatlin as the "hardest race" of his career.
The Jamaican, 29, lived up to his billing as the saviour of athletics as he held off the challenge of the two-time drug cheat to win in 9.79 seconds.
Pre-race favourite Gatlin had to settle for silver in Beijing.
"Coming back from injury I've had a lot of doubters, it's been tough," Bolt said after winning a ninth world title.
He added: "For me to come to the championships and defend my title is a good feeling.
"I definitely think this was my hardest race. I've been through a lot this season."
Bolt, back at the scene of his first triple Olympic triumph in 2008, called his Munich-based doctor, Hans-Wilhelm Muller-Wohlfahrt, "a lifesaver".
He also insisted he did not feel the pressure to win for his sport, only to continue his own global domination.
And that looked on course to end after the semi-finals when Gatlin clocked 9.77secs, while Bolt almost tripped out of the blocks and had to fight all the way to the line to snatch the win.