DES MOINES, Iowa -- In workouts, Dalilah Muhammad has often been on world-record pace.

On a drizzly Sunday night, she put everything together. Muhammad broke a 16-year-old world record in the 400-meter hurdles by finishing in 52.20 seconds at the U.S. championships.

"I'm just shocked," Muhammad said. "I broke the world record."

With puddles formed on the track, the reigning Olympic champion sloshed her way to eclipse the mark of 52.34 set by Yuliya Pechonkina of Russia on Aug. 8, 2003.

Running out of the fourth lane, Muhammad didn't let the rain drops deter her. The 29-year-old looked at her time and was almost taken aback.

No way that can be real, right?

It was.

Dalilah Muhammad poses after winning the women's 400-meter hurdles in a world-record 52.20 seconds Sunday at the U.S. championships. Kirby Lee/USA TODAY Sports

Muhammad smiled, briefly put her hands on her hips and then slumped down when her time flashed on the screen at Drake Stadium. Third-place finisher Ashley Spencer bounded over to congratulate her as well as teenager Sydney McLaughlin, who hugged Muhammad after finishing second.

To think, Muhammad fell in a training session two weeks ago and suffered a mild concussion. She missed three days of workouts to heal.

She lost none of her speed. Then again, the level of the competition brought out the best in her. A world-class field was assembled -- even at nationals.

Muhammad said she believes the record is not going to last long. It might even fall again at the world championships this fall in Doha, Qatar. Defending world champion Kori Carter didn't even compete at nationals in the event since she has an automatic bye into worlds.

"That 52 is going to get broke," Muhammad said. "If not by me by the other women."

McLaughlin finished in 52.88.

"It was a really fast race and I could feel the pace being pushed," McLaughlin said. "I'm happy to be a part of a world-record race. It's awesome."

Muhammad's performance stole the show.

Later in the night, Dezerea Bryant won the 200 in 22.47 seconds.

"I woke up this morning and I'm like, 'I'm not going to be denied," Bryant said. "That was my attitude."

Noah Lyles closed out the competition in style by doing a nifty little dance after taking the men's 200 title in 19.78. He held off Christian Coleman and, after crossing the line, shook his rival's hand before breaking off some dance moves.

The 22-year-old Lyles can certainly celebrate.

"Joy? Tons of joy. This is the hardest team to make," said Lyles, who sprayed his hair gray. "The saying is, once you make the U.S. team, you better come away with a medal."

Things to know on the final day of nationals:

COBURN'S DOMINANCE

Reigning world champion Emma Coburn captured her sixth consecutive national title in the steeplechase (eighth overall). She finished in 9 minutes, 25.63 seconds to edge Courtney Frerichs. Colleen Quigley was third. With Coburn getting an automatic bye, fourth-place finisher Allie Ostrander also is going to Doha.

GONE FISHING

Donavan Brazier is celebrating his berth at worlds by taking a fishing trip to Michigan.

"I would've gone either way,'' he cracked.

The 22-year-old Brazier won the 800 in 1:45.62 to beat Clayton Murphy, his training partner at the Nike Oregon Project. University of Kansas runner Bryce Hoppel was third.

HOULIHAN'S DOUBLE

Cheered on by a friendly crowd, Shelby Houlihan, a native of Sioux City, Iowa, won the 5,000. She also captured the 1,500 crown.

"Iowa strong, baby!'' Houlihan said.

NICE 'STACHE

Craig Engels stands out with his mullet even if it might not be the most aerodynamic haircut. He's also rocking a mustache.

"I just wanted to be different,'' said Engels, who won the men's 1,500 over Matthew Centrowitz. "This is what I landed on.''

LOMONG WINS AGAIN

Lopez Lomong won the 5,000 after taking the 10,000 earlier at nationals. He doesn't have the world qualifying standard in the 5,000.

"I'm just going to concentrate a little more on the 10,000 meters and see what I could do on the world stage,'' Lomong said.

Lomong fled Sudan to avoid a militia group when he was a child. He lived in a refugee camp for 10 years and became an American citizen in 2007.

MORE WINNERS

Nick Christie (men's race walk), Katie Burnett (women's race walk), Valarie Allman (discus), Erica Bougard (heptathlon), Ajee Wilson (800), Daniel Roberts (110 hurdles), Chase Ealey (shot put), Ja'Mari Ward (long jump) and Sandi Morris (pole vault).

SHE SAID IT

"It really just gave me more confidence. I can race with every woman, not just in the U.S. but probably in the world,'' said Athing Mu, who turned 17 and will be a high school senior in New Jersey this fall. She finished fifth in the women's 800 in a personal-best 2:01.17.