Once again, Usain Bolt was called upon to save track and field.
And once again, the incomparable Jamaican delivered.
With heavy rain falling at the Luzhniki Stadium and thunder and lightning in the air over Moscow, Bolt powered past American Justin Gatlin to reclaim the 100m title he lost in controversial circumstances after false-starting two years ago in Daegu.
The winning time was 9.77 seconds, with Gatlin taking silver in 9.85 and Nesta Carter the bronze in 9.95 as Jamaica placed four runners in the top five.
In many ways, a Gatlin victory would have been a nightmare for the sport which is once again mired in doping issues.
The Athens Olympic champion has twice tested positive to banned substances and was hit with a four-year ban after the second breach, only returning to competition in 2010.
Sunday's final was also about who wasn't there.
Leading American Tyson Gay and former world record holder Asafa Powell have recently failed drugs tests, while Jamaica's 2011 world champion Yohan Blake has had his season ruined by a hamstring injury.
So, once again, it all came down to Bolt.
"It's always great to get back your title," he said.
"I'm happy with myself I got it done.
"I'm just doing my part by running fast, winning titles and letting the world know you can do it clean.
"My focus is to continue doing what I do."
Midway through the race, Gatlin thought he was in with a real shot of causing what would have been a massive boilover.
"Then I saw these long legs coming up on my right side," Gatlin said.
"He's great. He's just great."
Bolt now has six Olympic and six world titles to his name and few would bet against him adding another two in the 200m and the 4x100m relay in the next seven days.
If he wins a third sprint treble in Moscow, he will draw level with fellow track legends Michael Johnson and Carl Lewis with eight world crowns.
"I am happy but I wanted to do better," said Bolt.
"My legs were sore after the semi-finals, I don't know why but the world record wasn't on so I came out just to win.
"Back in Jamaica, they do not expect less than that from me.
"They always expect me to dominate."
Bolt was the undisputed star of the show - as he is just about every time he runs.
But among the other winners on the second night of finals at the world titles was another of the sport's great champions, Tirunesh Dibaba of Ethiopia, who produced a withering last lap to win a third world 10,000m title and her first since 2007.
Dibaba's haul of major titles almost challenges Bolt, as it also includes 5000m world championships golds in 2003 and 2005 and two Olympic 10,000m gold medals.
Dibaba - who missed the 2011 world titles in Daegu due to injury - won in 30 minutes 43.35 seconds ahead of Kenya's Gladys Cherono and fellow Ethiopian Belaynesh Oljira.
Croatian powerhouse Sandra Perkovic added the world discus title to her London Olympics one, dominating Sunday's final with the three biggest throws of the night, including her gold medal effort of 67.99m.
American Britteny Reese won a third straight world long jump title with a best of 7.01m - 2cm clear of Nigeria's Blessing Okagbare, who is also among the gold-medal chances in Monday's 100m final.
Other gold medals decided on Sunday went to American Olympic champion Ashton Eaton in the decathlon and Russian Aleksandr Ivanov in the men's 20km walk.
