Allyson Felix stayed on course for a record-breaking 10th Olympic medal on Wednesday, comfortably cruising into the final of the women’s 400m.

The 35-year-old golden girl of US athletics, who is bidding to become the most decorated female Olympic track and field athlete in history, clocked a season best 49.89sec to finish second in her semi-final.

Jamaica’s Stephenie Ann McPherson took first place with a personal best time of 49.34, the fastest time of the semi-finals.

Felix, who is competing in her fifth and final Summer Games, is tied with Jamaican legend Merlene Ottey as the most decorated female track athlete in Olympic history on nine medals.

Reigning Olympic champion Shaunae Miller-Uibo of the Bahamas also advanced safely, winning her semi-final in 49.60.

Marileidy Paulino of the Dominican Republic won the remaining semi-final in 49.38, with Candice McLeod second in 49.51.