New York - Elle Purrier clocked the second-fastest indoor mile in history on Saturday, delivering a blazing finish to win the Millrose Games women's mile in 4:16.85.
Purrier sliced nearly four seconds off the American national record set by Mary Slaney 37 years ago.
She was pushed to the limit by runner-up Konstanze Klosterhalfen, whose 4:17.26 was a German national record, with Britain's Jemma Reekie third in a national record of 4:17.88.
"I just held on for dear life and kicked as hard as I could," Purrier gasped after moving up from third and holding off Klosterhalfen in the final straight.
Her time is second fastest ever indoors behind the 4:13.31 clocked by Ethiopia's Genzebe Dibaba in 2016 - supplanting the 4:17.14 produced by Romanian Doina Melinta back in 1990.
Purrier wasn't the only American national record-breaker at the Armory in New York City.
Donovan Brazier lowered the US indoor 800m record again with a victory in 1:44.22.
The 2019 outdoor world champion broke the mark of 1:44.41 he set in winning at Millrose last year.
"When I saw the clock going 1:42, 1:43, I was like, 'Oh, I have a chance," Brazier said.
"To get it by point-two seconds, there's really not much room for error there."
Ajee Wilson lowered her national 800m record to 1:58.29.
Brazier's world title has raised expectations that he can become the first American since 1972 to win an Olympic 800m gold.
"I think the target's on my back just because I won 2019," said Brazier, who said he did didn't think the weight of expectations he faces is anything close to those David Rudisha carried after setting the world record in a scintillating 2012 Olympic victory.
"I'm not thinking that I'm like this David Rudisha takeover because I'm not really damn near close to his times, but I think, for now, I've got that small target on my back. I guess I'm just trying to make it as big as possible," he said.
The indoor season wraps up with the USA Championships in Albuquerque, New Mexico, next week.
The World Indoor Championships originally scheduled for the Chinese city of Nanjing in March have been postponed until 2021 because of coronavirus fears.
America's 2016 Olympic shot put gold medallist Ryan Crouser said he'd changed his training regimen because of that news - which made his victory on Saturday with a throw of 22.19m all the more satisfying.
"Especially with the world championships being called off, I went back into heavy training, so really happy with it," he said.
Crouser said he was having no trouble keeping himself motivated for a repeat bid in Tokyo this year.
"It's the Olympics, it's not too hard to get motivated for that if you're a track and field athlete."
Top finishers from Saturday's 113th Millrose Games indoor athletics meeting:
60m: 1. Ronnie Baker (USA) 6.54sec, 2. Demek Kemp (USA) 6.56, 3. Kevaughn Rattray (JAM) 6.62
60m hurdles: 1. Daniel Roberts (USA) 7.64, 2. Xie Wenjun (CHN) 7.69 (7.684) 3. Chad Zallow (USA) 7.69 (7.689)
300m: 1. Rai Benjamin (USA) 32.35, 2. Justin Robinson (USA) 33.17, 3. Marcus Chambers (USA) 33.21
800m: 1. Donavan Brazier (USA) 1:44.22, 2. Bryce Hoppel (USA) 1:45.70, 3. Isaiah Harris (USA) 1:46.01
3 000m: 1. Justyn Knight (CAN) 7:46.36, 2. Joe Klecker (USA) 7:47.57, 3. Jordan Gusman (MLT) 7:48.17
Mile: 1. Chris O'Hare (GBR) 3:55.61, 2. Olli Hoare (AUS) 3:56.47, 3. Rob Napolitano (USA) 3:56.56, 4. Nick Willis (NZL) 3:56.72
Shot Put: 1. Ryan Crouser (USA) 22.19m, 2. Joe Kovacs (USA) 21.34, 3. Payton Otterdahl (USA) 21.10
60m: 1. Javianne Oliver (USA) 7.13, 2. Morolake Akinosun (USA) 7.16, 3. Briana Williams (JAM) 7.18 ... 6. Allyson Felix (USA) 7.32
60m hurdles: 1. Keni Harrison (USA) 7.90, 2. Nia Ali (USA) 7.96, 3. Payton Chadwick (USA) 8.00
400m: 1. Wadeline Jonathas (USA) 51.93, 2. Jaide Stepter (USA) 53.01, 3. Courtney Okolo (USA) 53.08
800m: 1. Ajee Wilson (USA) 1:58.29, 2. Natoya Goule (JAM) 1:59.35, 3. Olivia Baker (USA) 2:02.86, 4. Cynthia Anais (FRA) 2:04.51
3 000m: 1. Allie Ostrander (USA) 8:48.94, 2. Julie-Anne Staehli (CAN) 8:49.01, 3. Laura Galvan Rodriguez (MEX) 8:49.74
Mile: 1. Elle Purrier (USA) 4:16.85, 2. Konstanze Klosterhalfen (GER) 4:17.26, 3. Jemma Reekie (GBR) 4:17.88
High Jump: 1. Sandi Morris (USA) 4.91m, 2. Megan Clark (USA) 4.40, 3. Chloe Cunliffe (USA) 4.30