Olympic champion runs a time of 52.20 at USA Champs to improve on the 52.34 by Yuliya Pechonkina in 2003

Dalilah Muhammad stormed into the history books on Sunday as she clocked an incredible time of 52.20 to break the world 400m hurdles record at the USA Championships in Des Moines, Iowa.

Running in lane four on a wet track, and after starting with the slowest reaction time (0.287), the Olympic champion powered away and had a clear lead off the final bend as world under-20 record-holder Sydney McLaughlin, Olympic bronze medallist Ashley Spencer and 2015 world silver medallist Shamier Little battled behind her.

But Muhammad did not falter and went on to clock a mark which improves by 0.14 the previous record run by Yuliya Pechonkina almost 16 years ago.

McLaughlin came through to secure second in 52.88, while Spencer was third in a PB-equalling 53.11 and Little fourth in 53.91.

Before this year, Muhammad’s PB for the 400m flat had been 52.63 but she proved her fine form with a time of 50.60 in Poland in June and her new hurdles time – which moves her up from sixth with 52.64 on the world all-time list – is faster than many 400m runners can manage, without 10 hurdles on the track.

“I wanted it so bad,” Muhammad told NBC after the race. “I knew I had to go out there and prove myself.”

The final day of USA Championships action also saw Noah Lyles, fresh from his 19.50 in Lausanne, win the men’s 200m title in 19.78 ahead of 100m winner Christian Coleman’s 20.02. The women’s title was claimed by Dezerea Bryant in 22.47.

READ MORE: Noah Lyles storms to 19.50 200m in Lausanne

Donavan Brazier won the men’s 800m title in 1:45.62 from Clayton Murphy’s 1:46.01, while defending world champion Emma Coburn claimed her eighth US steeplechase title, clocking 9:25.63 ahead of Courtney Frerichs with 9:26.61.

Craig Engels took the men’s 1500m title in 3:44.93, just ahead of Olympic champion Matthew Centrowitz with 3:44.97.

World indoor champion Sandi Morris won the pole vault with a season’s best clearance of 4.85m as Katie Nageotte was second with 4.80m and 2012 Olympic champion Jenn Suhr third with 4.70m.

Lopez Lomong completed a 5000m and 10,000m double, running 13:25.53 ahead of Paul Chelimo’s 13:25.80 to win the men’s 5000m after his 10,000m victory on Friday, while Shelby Houlihan also secured two titles as she won the women’s 5000m in 15:15.50 to add to her 1500m title from Saturday.

READ MORE: Sam Kendricks clears 6.06m at USA Championships

World medallist Ajeé Wilson took the 800m title in 1:57.72, while Daniel Roberts won the 110m hurdles in 13.23 ahead of Grant Holloway’s 13.36.

Chase Ealey won the shot put with a 19.56m throw and Valarie Allman took the discus title with 64.34m, while Jeron Robinson claimed the high jump title with a 2.30m clearance and Ja’Mari Ward was the long jump winner with a leap of 8.12m.

Erica Bougard ran a 2:12.41 800m to move from second to first in the heptathlon, winning gold with 6663 points ahead of Kendell Williams with 6610 points.

Titles in the 10km race walk were won by Katie Burnett and Nick Christie in respective times of 46:12.45 and 41:56.61.

Coverage of day one and day two action can be found here, while a day three report is here and results are here.

» For more on the latest athletics news, athletics events coverage and athletics updates, check out the AW homepage and our social media channels on TwitterFacebook and Instagram