Usain summons a Bolt from the blue

Usain Bolt once again produced his best when it mattered most to retain his 100 meters world title on Sunday and reassert his status as the fastest man on the planet.

The 29-year-old Jamaican surged past American Justin Gatlin over the last 30 meters and crossed the line in 9.79 seconds, his fastest run of the year.

Gatlin finished second in 9.80 to take silver, while Andre de Grasse of Canada and American Trayvon Bromell tied for third place in 9.92.