The subject of doping won't go away and newly elected IAAF President Sebastian Coe, who officially took over the post on Sunday, has made it his No.1 priority.
But for a period that cloud lifted -- even amid the failed drugs tests of two Kenyan athletes -- and a sport some suggested was fighting for its life was able to shine.
The smog lifted too, albeit temporarily, thanks to preparations by the Chinese government for a key military parade on September 3.
With most of the capital's factories shut down, barbecues banned, and cars with odd and even number plates only permitted to be driven on alternate days, spectators and athletes alike were treated to clear, blue skies.
And under those skies no one shone brighter than Jamaican superstar Usain Bolt -- written off before the championships after a troubled season in which he was struggling with a pelvic problem and nowhere near the times we have become accustomed to.His sprint duel with Justin Gatlin, which spanned the sprint events -- 100m, 200m and 4x100m -- was in some ways a succinct summary of the sport in the 21st century: Bolt painted as the sport's savior, while Gatlin, twice banned for doping offenses, viewed by some as the pantomime villain.
However, the American sprinter, who had come into the championships unbeaten in 27 races, refused to speak to British media for what he deemed an unfair vilification.Usain Bolt show
But when it mattered he could not catch Bolt. A stumble in the final strides of the 100m final seeing him edged out by just a hundredth of a second -- that minuscule moment in time the difference between positive and negative headlines for the championships.
As it turned out, the only person capable of toppling the world's fastest man was a Segway-driving cameraman for host broadcaster CCTV, who became an overnight global sensation when he lost control of the two-wheel vehicle and his camera and took Bolt down with him.
