DES MOINES, Iowa -- Dalilah Muhammad broke a 16-year-old world record in the 400-meter hurdles by finishing in 52.20 seconds on a drizzly night at the U.S. championships.

With puddles on the track Sunday, the reigning Olympic champion eclipsed the mark of 52.34 set by Yuliya Pechonkina of Russia on Aug. 8, 2003.

Muhammad's previous best time was 52.64 in 2017.

Teenager Sydney McLaughlin was second and Ashley Spencer wound up third to also earn spots in the world championships in Doha, Qatar. Kori Carter didn't compete in the event but has an automatic bye into worlds as the defending champion.