The USA came into the Olympics with a rejuvenated squad and a point to prove after a poor showing at last year's World Cup, when they were eliminated in the last 16.
They also performed below par at each of the last two Olympics, finishing out of the medals at Rio 2016 before taking bronze three years ago in Tokyo.
But the arrival of renowned English coach Hayes from Chelsea has given the USA the boost they needed, and they have been inspired on their way to the final by the exciting attacking trio of Sophia Smith, Mallory Swanson and Trinity Rodman.
They have each scored three goals at the tournament, with the USA winning all three group games against Zambia, Germany and Australia before dispatching both Japan and the Germans in extra time in the knockout rounds.
Now they are hoping to add to their women's football record haul of four golds and win the title for the first time since London 2012.
"Emma came in so soon before this tournament, so we knew that was going to be a challenge, but she just came in flying and we absolutely love her," said Smith, the Colorado-born forward who turns 24 on the day of the final.
"She has worked every day to build our trust and show us she cares about us. She is such a great coach and such a great mentor.
"We are a completely different team and a lot of the credit goes to Emma. She has communicated everyone's roles very clearly. We are really excited for her to be our coach for a really long time."
Third time lucky?
The USA's position as the undisputed global powerhouse of the women's game looked to be gone for some time following last year's World Cup in Australia and New Zealand, when a brilliant Spain team led by Aitana Bonmati were crowned champions.
However, Spain missed out in their bid to add Olympic gold to that title and the UEFA Nations League after they were surprisingly beaten 4-2 by Brazil in Tuesday's semi-final in Marseille.
Instead it is the Brazilians who will meet the USA in the gold medal match and they will be attempting to make it third time lucky after losing to the same opponents in the Athens final in 2004 and in Beijing in 2008.
Both of those finals were won by the USA in extra time, and both featured Marta, the Brazilian legend and multiple winner of the FIFA world player of the year award.
Now 38, she is appearing at her sixth and likely last Olympics, and is hoping to sign off with gold to go with her two silver medals.
Marta back from ban
Marta missed both the quarter-final win against hosts France and the semi-final against Spain due to suspension after being sent off for a reckless challenge in Brazil's final group game, also against the Spanish.
"Now she will be able to finish her Olympics playing in a final, where she deserves to be. I hope she manages to come away with the gold medal," said Gabi Portilho, who scored in both the quarter-final and semi-final.
It remains to be seen if the final will turn out to be Marta's farewell on the international stage for her country, or whether she could be tempted to keep going until the 2027 World Cup which Brazil will host.
"Marta has changed the game of soccer around the world," said Rodman of Marta, who has spent much of her club career in the United States.
"She is such a talented soccer player but also a great human. I have always looked up to her. She has a legacy forever, but we want that gold."
