[2] Shaunae Miller-Uibo won the gold medal by 0.84 seconds in a personal best of 48.36 secs, a time which ranks her sixth on the world all-time list.

Returning from Rio was Gold Medalist Shaunae Miller-Uibo, remembered for her diving finish to beat Allyson Felix.

But the list of non-participants is notable; World Champion Salwa Eid Naser suspended a little over a month before the Olympics due to three whereabouts failures; Olympic and World Championship bronze medalist Shericka Jackson, who focused her season on the shorter sprints, netting a bronze medal in the 100 metres; Namibian teenage sensations Beatrice Masilingi, number one in 2020 and Christine Mboma who ran the #7 time in history the same day Eid Naser was suspended, both were barred from running 400 or 800 due to the new Testosterone regulations.

Another teenager, NCAA Champion Athing Mu, chose to focus her efforts on the 800 metres, netting a gold medal.

Marileidy Paulino was the fastest qualifier at 49.34, her Dominican National Record, putting her in the center of the track, lane 5 for the final.

The Jamaicans Stephenie Ann McPherson and Candice McLeod in 6 and 4 respectively, were the fastest around the first turn, with Felix, blind to her competitors in lane 9, also getting out well.

Roxana Gómez pulled up after 100 m. Coming off her poor performance in the 200 final, Miller-Uibo ran conservatively in the first 200 metres, still keeping in close contact with Felix well within her view from lane 7.

Felix nabbed her tenth Olympic medal, breaking a tie with Merlene Ottey as the most of any woman in athletics and set her third Masters World Record of the season.