The 24-year-old swimmer came from behind to win a thrilling all-American tussle, touching the wall first in 4min 2.39sec - just one second ahead of Long.

Long looked in a strong position to reclaim the title she had lost at Rio 2016 as she led by two seconds at the halfway stage.

But Stickney demonstrated all the guts and determination that saw her overcome her double leg amputation to claim a first Paralympic title.

"Everything I've been through in the past few years kind of flashed before my eyes," said Stickney.

"I remember sitting in the hospital just dreaming of being able to go to the Paralympic Games, and then the pandemic happened and it became a reality that I could come here.

"Trying as hard as I could and training in the last year, being able to be here and then to get the gold medal is just such an honour."

Ten years ago, Stickney was considered a future Olympian as she was one of the best swimmers in her age group in the US before suffering a life-changing foot injury.

She underwent a series of surgeries before a decision was taken to have her lower left leg amputated in May 2018.

A year-and-a-half later, Stickney had her right leg amputated following another injury to her foot and being diagnosed with a condition that cuts blood supply.

Stickney had to relearn how to walk and swim again but refused to give up on her dream of competing in Tokyo and is now a Paralympic champion.

"Since everything I've been through, it's such an honour, and it's something that I could have never imagined," she said.

Long came second in 4:43.41 with Francesca Xenia Palazzo of Italy finishing third in 4:56.79.

Stickney’s showdown with Long was one of 14 finals that took place at the Tokyo Aquatics Centre today.

Sophie Pascoe - New Zealand’s most decorated Paralympian - added a 10th gold to her collection after triumphing in the women’s 100m freestyle S9 final.

The 28-year-old pulled clear to win in 1:02.37 as Spain's Sarai Gascon sealed silver in 1:02.77, while Brazil's Mariana Ribeiro bagged bronze in 1:03.39, edging out Britain's Toni Shaw by just 0.03 seconds.

Ukraine's Andrii Trusov claimed his second gold of the Games with victory in the men’s 50m freestyle S7 final.

Trusov clinched the title in 27.43 - 0.41 ahead of Colombia's Carlos Daniel Serrano Zarate, who finished in 27.84.

The bronze medal went to Yevhenii Bohodaiko, who touched the wall 27.99.

Spain's Marta Fernandez Infante stormed to victory in the women’s 50m breaststroke SB3, winning in 58.21.

Nataliia Butkova of the Russian Paralympic Committee (RPC) dug deep to secure the silver medal in 1:00.54, with Mexico's Nely Miranda Herrera taking bronze in 1:01.60.

Arnulfo Castorena of Mexico swept aside the rest of the field to claim the men's 50m breaststroke SB2 in emphatic fashion.

He led from start to finish as he powered to his third Paralympic title in 59.25.

Grant Patterson of Australia came second in 1:01.79, with Jesus Hernandez Hernandez finishing third in 1:02.27.

Valeriia Shabalina of the RPC completed a hat-trick of gold medals at Tokyo 2020 with victory in the women’s 200m individual medley SM14.

The 26-year-old, who triumphed in the 200m freestyle S14 and 100m butterfly S14, finished first ahead of two British swimmers in 2:20.29

Bethany Firth took silver in 2:23.19 with Louise Fiddes coming third in 2:29.21.

Britain’s Reece Dunn delivered a superb finish to break the world record and clinch the men’s 200m individual medley SM14 title - his third gold of the Games.

Ukraine's Vasyl Krainyk led going into the final 50m before Dunn, a winner of the 200m freestyle S14 and mixed 4x100m freestyle relay S14, found an extra gear to secure victory in 2:08.02, beating the world record by 0.14 seconds.

Gabriel Bandeira of Brazil took silver in 2:09.56 as Krainyk slipped to third in 2:09.92.

Maria Carolina Gomes Santiago of Brazil secured her second gold of Tokyo 2020 after edging Daria Pikalova of RPC in the women’s 100m freestyle S12 final.

The 36-year-old Brazilian, a gold medallist in the 50m freestyle S12, touched the wall first in 59.01sec - just 0.12 seconds ahead of Pikalova.

Britain's Hannah Russell came third in 1:00.25.

Raman Salei of Azerbaijan came from behind to beat former champion Maksym Veraksa of Ukraine to gold in the men's 00m freestyle S12 final.

Veraksa led at the turn before Salei roared back to win in 52.69.

The London 2012 champion was second in 52.87 as Stephen Clegg of Britain finished third in 53.43.

Andrei Nikolaev of the RPC withstood Mexican Alberto Amodeo's fightback to clinch gold in the men's 400m freestyle S8, finishing in 4:25.16.

Amodeo piled on the pressure but had to settle for silver in 4:25.16, with Matthew Torres of the US taking bronze in 4:28.47

Italy's Giula Terzi produced a Paralympic record-breaking time of 1:09.21 to upset defending champion McKenzie Coan in the women’s 100m freestyle S7 final.

Coan, winner of all three freestyle events at Rio 2016, came second in 1:10.22 while S6 swimmers Yelyzaveta Mereshko of Ukraine and China's Jiang Yuyan shared bronze after both finishing in a world record of 11:11.07.

World and European champion Maksym Krypak of Ukraine captured the men’s 100m butterfly S10 crown with a world record time of 54.15.

Italy's Stefano Raimondi finished second in 55.04 and Australia's Col Pearse collected the bronze medal in 57.66.

Mikaela Jenkins of the US edged out Jasmine Greenwood of Australia in a closely-fought women’s 100m butterfly S10 final.

Greenwood led for much of the race only to be pipped to the touch by Jenkins, who clocked 1:07.52.

The Australian picked up silver in 1:07.89, while Chantelle Zijderveld of The Netherlands sealed bronze in 1:07.91.

In the last race of the day, the RPC toppled Brazil to win mixed 4x100m freestyle relay gold in a Paralympic record.

Brazil were leading going into the final leg before Vladimir Sotnikov overtook Gomes Santiago to secure gold for the RPC in 3:53.79.

The silver went to Brazil in 3:54.95, while Ukraine earned bronze in 3:55.15.