The Rio Olympic champion, Muhammad, clocked 52.20 seconds shaving 0.14 seconds from the previous record.
The-29-year-old Muhammad's previous personal best was 52.64 set in 2017.
“My coach kept telling me it was there,”
“I just had to trust in my fitness and go for it.” Muhammad told NBC.
The 19-year-old Sydney McLaughlin finished second in a season's best of 52.88 just 0.13 shy of her personal best, while Ashley Spencer equaled her life time best of 53.11 to take third.
The 22-year-old Noah Lyles won the 200m final in 19.78 seconds. He defeated U.S. 100m champion Christian Coleman, who crossed the line second in 20.02. Ameer Webb set a seaon's best time of 20.45 to take third place.
Lopez Lomong, who won the 10,000m on Thursday, blazed 53.35 in the last 400m to win the 5000m in 13:25.53 ahead of Paul Chelimo (13:25.80) and Woody Kincaid (13:26.84).
In the women's heptathlon, Erica Bougard clocked 2:12.41 in the final event the 800m to overcame Kendell Williams‘ 66-point lead to defend her U.S. title. Bougard totaled 6663 points, the 3rd best performance this year in the World. Kendell Williams set a new personal best and 2019 World #4 with 6610 points to take second place.
In the women's 200m final Dezerea Bryant prevailed with 22.47 seconds with Brittany Brown in second in 22.61.
Craig Engels was a surprise winner in the men's 1500m final in 3:44.93. In a thrilling sprint finish Engels managed to hold off Olympic 1500m champion Matthew Centrowitz by 0.04 seconds. Centrowitz finished in second pace to make his seventh straight U.S. Olympic and or world championships team. Josh Thompson claimed third place with a time of 3:45.25.
Donavan Brazier was the winner in the men's 800m (1:45.62). The Rio Olympics bronze medalist Clayton Murphy in the final 100m went from fourth to 2nd while Bryce Hoppel made his first US World Championships team by taking third.
Ajeé Wilson comfortably won her third straight U.S. 800m title with a time of 1:57.72.
Shelby Houlihan who won the 1500m a day earlier won the 5000m on Sunday. Houlihan is not expected to race the 5000m at World champiosnhips in Doha as she is focusing on the 1500m.
Defending World champion Emma Coburn won her eighth U.S. 3000m steeplechase title in nine years. Courtney Frerichs, the 2017 World silver medalist and Amrican record holder in the event took second place while Colleen Quigley concluded the podium.
In the men's 110m hurdles final, Daniel Roberts took the title in 13.23 beating Grant Holloway, the World leader in the event with 12.98, and the 3-time U.S. champion Devon Allen. Holloway dived across the finish line to take second securing his first world U.S. team. Allen who took third place clocked 13.38 seconds only 0.01 seconds ahead of Freddie Crittenden.