Competition for the title of World's Fastest Man between Michael Johnson of USA and Donovan Bailey from Canada on a 150m track. After the 1996 Olympics.
Longer version of the race here.

From Wikipedia:
"The unofficial title of "world's fastest man" typically goes to the Olympic 100 m champion, but in 1996 many, particularly in America, pointed out that Johnson's gold-medal performance in the 200 m (19.32) was faster than Bailey's 100 m performance (9.84) in that 19.32 divided by two is 9.66 seconds. Bailey's defenders also noted that the 200 m time is almost always "faster," and each 200 m gold medalist from 1968 when fully electronic timing was introduced to 1996 had a "faster" time at the Olympics, save one, yet there had been no controversy over the title of "world's fastest man" previously.

In 1997, Johnson began performing television promotions in which he billed himself as "the world's fastest man". Bailey initially refused to challenge, stating that "the world's fastest man was decided in Atlanta". After verbal sparring between the pair, a made-for-TV, 150-metre showcase at Toronto's SkyDome (now renamed as the Rogers Centre) was scheduled."