Bolt gets gold No. 9 with another runaway win

Japan won the silver medal, finishing .33 seconds behind. The U.S. finished the race third but endured yet another relay debacle -- disqualified because leadoff runner Mike Rodgers passed the baton to Justin Gatlin outside the exchange zone. That promoted Canada to the bronze medal.

This marked the ninth time since 1995 the U.S. men have been disqualified or failed to get the baton around at Olympics or world championships. That will cause more hand-wringing in the States.

In Jamaica, they'll party. Bolt's record in Olympic finals: Nine races, nine wins. Nobody's done that before, and nobody's on the horizon to do it again soon.

Along with Bolt for his final trip down the track were Nickel Ashmeade, training partner Yohan Blake and the Jamaican elder statesman, former world-record holder Asafa Powell. When Bolt received the yellow baton from Ashmeade for his final run down the straightaway, he was even, maybe a step behind, Aska Cambridge of Japan and Trayvon Bromell of the United States. That lasted about four steps.

With 70 meters to go, it was all over. Bolt looked at the clock -- same as he did when he finished the 200-meter victory the night before.

No world record, but he still has a piece of that one, too -- it's 36.84 seconds, set four years ago at the London Games.

Musical selection for Bolt's final parade around the track: Bob Marley's "Jammin." With most of the other debates over about greatest this, greatest that, a new one might be whether Bolt now surpasses Marley as the most famous person to rock the world from the country known for sea, sun and sprints.

Counting all the preliminaries, finals and his approximately nine-second blast down the stretch in last night’s last race, Bolt has spent 325 seconds -- a tad less than 5 1/2 minutes -- running on the track at the Olympics since he made his debut in Beijing eight years ago.

Every tick of the clock has been a treasure. And while he may not close things out with 23 golds, the number Michael Phelps left Rio with earlier this week, it's hard to argue there is anybody more successful or electric -- or important to his sport, and the Olympics themselves.

The anchor sport of the Olympics has been mired, especially over the past year, in a cesspool of doping, cheating and bad characters.