Jackson appeared to slow up just before the finish line during the heat, which allowed Italy’s Dalia Kaddari to pass her in the final moment. She finished four-thousandths of a second behind Kadari.
Jackson finished in fourth place and Kaddari finished in third. The first three runners in each heat advanced to the semifinals.
“Obviously she misread and she paid the price,” Jamaican coach Stephen Francis told The Gleaner. “I expected her to do better but she didn’t and I can see why, but she will learn.”
She won a bronze medal in the 400-meter and a silver medal in the 4×400-meter races in the 2016 Rio Games.
Jackson was coming off a bronze medal in the 100-meter race. Elaine Thompson-Herah and Shelly-Ann Fraser-Pryce both advanced to the semifinals in the 200-meter.
Thompson-Herah was fresh off of a record-setting 100-meter finish. アメリカのエリンジャクソンはオリンピックスピードスケートの金メダルで歴史を作ります 10.61 seconds and broke the 33-year-old Olympic record held by American Florence Griffith Joyner.
“I think I could have gone faster if I wasn’t pointing and celebrating, 本当に,” Thompson-Herah said. “But to show you that there’s more in store. うまくいけば, one day I can unleash that time.”