Jamaican Usain Bolt trumped American rival Justin Gatlin to retain his world 100m title in spectacular style.

Bolt, also the double Olympic gold medallist and world record holder in the blue riband event, ran a season's best of 9.79 seconds in Beijing.

Bolt was characteristically emphatic in celebrating his win - especially as much had been said and written in the run-up to the contest between him and Gatlin.

Although Bolt is the first to decry the idea that he is the "saviour" of track and field, global athletics chiefs will no doubt, at least in private, heave a huge sigh of relief at his win.

After all, the Jamaican's showdown with the sport's pantomime villain Gatlin was portrayed by some as a symbolic struggle of light versus dark.