McPherson ran a season-best 50.15 to win the second heat as the cast of Caribbean women stamped their class on the opening round. Also through was Olympic champion Shaunae Miller-Uibo who won her heat in 51.10, after literally jogging the last 80m.
Also enjoying safe passage through to the next round were Olympic silver medallist Marileidy Paulino, who was also impressive while winning her heat in 50.76. Her compatriot, Fiordaliza Cofil, who was also impressive while winning her heat in 51.19.
Sada Williams of Barbados cruised to victory in her heat in 51.05. Aliyah Abrams of Guyana was also an automatic qualifier after finishing second in her heat in 51.98. Jamaican champion Candice McLeod eased up and finished second in her heat clocking 50.76 to automatically qualify for the next round.
A tired-looking Charokee Young, who finished fourth in her heat, qualified as one of the fastest losers while Puerto Rico’s Gabby Scott and Cuba’s Roxana Gomez are also through to the next round.