Dick Button last won five in a row amid seven straight, 1946-52. Chen wins his 12th consecutive gold since 2018, while Vincent Zhou and Jason Brown capture silver, bronze.
The drive for five for Nathan Chen is complete.
The American, a two-time world champion, captured his fifth consecutive U.S. Figure Skating Championships victory on Sunday in Las Vegas, skating to first place ahead of compatriots and fellow Olympians Vincent Zhou (silver) and Jason Brown (bronze).
Chen, 21, won with a score of 322.28. Zhou came in at 291.38 and Brown with a 276.92.
Yaroslav Paniot finished fourth.
Chen is the first U.S. man to win five in a row since two-time Olympic gold medallist Dick Button won seven straight from 1946 to 1952. Michelle Kwan was the last singles skater to do so, winning eight in a row from 1998 to 2005.
"It's incredible," Chen told NBC Sports afterward. "Dick has been an inspiration for all skaters since he won his seven in a row. It's incredible to be able to try to follow in his footsteps and look forward to where figure skating continues to go."
"I still have a lot to go, a lot more that I can continue working on and improving. This program wasn't perfect. And I know there's a lot of things that I can immediately try to work on, assuming a worlds happens so that I can perform it a little better there. As of now, I'm happy with where I am, how I skated and the future will come." -- Nathan Chen
The event, being held at the Orleans Arena, had strict COVID protocols for the athletes and did not include fans.
U.S. Figure Skating announced its world championships team for March, with Chen, Zhou and Brown selected for the men, Tennell and Karen Chen for the ladies, Knierim/Frazier and Jessica Calalang and Brian Johnson in pairs, with Hubbell/Donohue, Madison Chock and Evan Bates and Kaitlin Hawayek and Jean-Luc Baker for ice dance.
Chen had a shaky start in his free skate on Sunday afternoon, putting his hands down to save the landing on his opening quadruple Lutz, which lost him 4.14 points on the Grades of Execution (GOEs). But he rebounded nicely thereafter in the program, set to Philip Glass, a free skate that builds as it goes, ending in a choreography sequence and combination spin.
Chen, dressed in sleek all black for the free skate, joins the likes of other top-ranked men in the figure skating world in now turning his attention - they each hope - to worlds in March, still scheduled for Stockholm.
"It's definitely been a strange season not being able to see (Hanyu) Yuzu and (Uno) Shoma and (Mikhail) Kolyada and all these amazing skaters. I know I left out a lot of a lot of names there. But, you know, it's been really strange to not be able to see them. But fortunately, I have a great (training team). And so that's been great for me."
Even with his mistake on the quad Lutz, Chen was never in any true danger after Zhou singled a planned quad flip in his free skate. He would later fall on an under-rotated quad Lutz. Zhou was solid otherwise in his long program, hitting two quad jumps, including a "Rippon" (arms over his head) quad Lutz-triple toe in combination.
It's his third career silver at nationals.
Brown, the Sochi 2014 team bronze medallist at the Olympics, was stunning in his short, the "Sinnerman" program set to be used next season as well as he aims to get back onto the Olympic team having missed out in 2018. He too, however, didn't have his best day at the office in the free skate, falling on an opening quad toe and then singling a planned triple Axel.
The U.S. will likely have three Olympic spots, and all three podium finishers have stated intent of going, of course.
"I have a similar approach to Nathan - in a different way: In 2018, my biggest fear came true, I didn't make the Olympic team," Brown told reporters, according to Rocker Skating. "After making it in 2014, my mindset was just on making that team. I was skating (more) out of fear than out of determination to get back. I'm so determined to get back on the team... my heart, my soul, my mind are all there."
Panoit, who was fourth, formerly skated for Ukraine and is still not able to compete internationally for the U.S. Fifth-place finisher Maxim Naumov is the reigning U.S. junior champ, while other up-and-comers include Tomoki Hiwatashi, the 2019 world junior champ, who finished seventh, and eighth-place finisher Camden Pulkinen.