PARIS — Since qualifying for the Olympics in 2021 only to be barred from competing, Sha’Carri Richardson had waited three years for the second chance that arrived Saturday night.

Separated, finally, from the Olympic gold medal she has long pursued by just 100 meters of a purple track Saturday evening inside Stade de France, the American star coiled into the blocks amid falling rain and waited to reassert her title as the fastest woman in the world.

Yet right from the gun, Richardson was…