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U.S. Paralympic swimmers Anastasia Pagonis and Gia Pergolini, both 17, each claimed gold in world record-breaking fashion on Thursday. Pagonis won America's first gold medal of the Tokyo Paralympics in the women's S11 400-meter freestyle while Pergolini placed first in the S13 100-meter backstroke. 

The first-time Paralympians can bask in their medal-winning glory together, as they've become fast friends while rooming together in Tokyo. 

"I remember waking up this morning and [Pagonis] was like, 'This is the day, Gia. You got this,'" Pergolini told NBC after her race. "And I said, 'You got this too.' And we just love each other and love supporting each other." 

The Paralympians' mutual support led to two record-shattering performances. 

Pagonis broke the world record she set herself at the U.S. Paralympic Swimming Trials with a time of 4:54:49, 10 seconds faster than the silver medalist Lissette Bruinsma of the Netherlands. Pergolini broke her event's world record twice within a 10-hour span, first in her preliminary heat with a 1:05.05 and then again in the final with a 1:04.64. 

"I'm so excited we're able to be here and we're both world-record holders," Pagonis, who completely lost her sight to genetic retina disease and autoimmune retinopathy at age 14, told the Olympic Information Service.

Pagonis is competing in the S11 class, which is for Paralympians with the greatest visual impairments. Pergolini -- who began losing her sight to Stargardt disease as a kindergartener -- is classified as an S13 Paralympian, meaning she's visually impaired but not the extent of S11 and S12 athletes. 

After her record-breaking win, a dancing and medal-toting Pagonis posted a TikTok with the caption, "My back hurting from carrying my gold medal." She has over two million followers on the social media platform. 

Pagonis can add to that weight on her back in these Paralympics as she's yet to compete in the 50-meter freestyle, 100-meter freestyle and the 200-meter individual medley. Pergolini is slated to race in the 50-meter freestyle.