LAUSANNE, Switzerland (AP) — Caster Semenya failed to hit the heights of the last time she competed in a 1,500-meter race as she finished sixth in a Diamond League meeting in Lausanne, just a stone's throw away from where her legal battle over the IAAF's female classification regulations will be fought at the Court of Arbitration for Sport.

The race on Thursday was won by Shelby Houlihan of the United States, who ran a personal best of 3 minutes, 57.34 seconds to beat Britain's Laura Muir, who clocked a season best of 3:58.18.

Sifan Hassan of the Netherlands was third in 3:58.39.

Semenya, who set a South African national record of 3:59.92 in Doha in May, was more than three seconds slower than Houlihan, with a time of 4:00.44.

The IAAF has ruled female runners too high in natural testosterone can't race in track events from the 400 to the mile unless they take medication. It comes into effect in November, but Semenya has challenged the rule at the Court of Arbitration for Sport.