The 24-year-old simply stood there soaking up the atmosphere created by a raucous Arthur Ashe Stadium.
It felt like a pioneering moment in the career of the American; a culmination of hard work and raw talent that has long been heralded as the potential future of men’s tennis in the country.
Expectations of Tiafoe have been high for a long time and the world No.26 now looks more than comfortable on the sport’s biggest stage.
Should Tiafoe reach the semi-finals by defeating Andrey Rublev on Wednesday, he would record the best grand slam result of his career and the feat will be made all the more impressive by his humble beginnings.
Tiafoe’s route into tennis, after all, was by no means traditional.
Their father, Constant Tiafoe, started working at the Junior Tennis Champions Center in Washington back in 1999 and later moved into one of its vacant warehouses working around the clock.
His two boys sometimes stayed with him, sleeping on a massage table, while their mother worked night shifts as a nurse.
The unusual entrance into the sport gave Tiafoe a chance to start developing his skills and, after starting training at the facility, he didn’t look back.
Driven by his parents’ work ethic, he won the prestigious Orange Bowl — one of tennis’ most prestigious junior tournaments — at age 15, becoming the youngest boys’ singles champion in the tournament’s history.
He joined a list of previous champions that included Roger Federer, Andy Roddick, Ivan Lendl, Jim Courier, John McEnroe and Bjorn Borg.
It was a sign of things to come.
Maturing on tour
Tiafoe turned pro in 2015 and began to familiarize himself with the rigors of the senior tour.
He broke into the world’s top 100 and began to assert himself at grand slams — reaching his first quarter-final at the 2019 Australian Open before losing to Nadal.
Three years later and he finds himself at another quarter-final, only this time he feels more ready to seize the opportunity.
“Honestly, when I first came on the scene, I wasn’t ready for it mentally and mature enough,” he said on court after beating Nadal. “I was able to develop and I have a great team around me.
“I’m glad I won in front of my mom, my dad, my girlfriend and my team and for them to see what I did.”
As he cements himself as a contender on the court, Tiafoe also pursues social justice off of it.
In 2022, he told CNN Sport that the lack of diversity in the sport made him feel like an “outsider”, and he vowed to continue fighting for equality while he still had the platform to do so.
He created a protest video in 2022 to raise awareness of racial injustices after the death of George Floyd sparked protests around the world.
In collaboration with a host of black players and coaches — such as Serena Williams and Coco Gauff — he posted the “Rackets down, hands up” video to his social media.
On the court, his next match against Rublev will surely be the biggest of his career so far.
The home crowd will be hoping that its hero can continue to hit new heights in his bid to win a maiden grand slam title.
His performances have even attracted the attention of some of the biggest names in sports, with NBA star LeBron James congratulating Tiafoe on making the quarterfinals.
Make no mistake, however, this is not an overnight success story. It’s a product of thousands of hours of work and a mindset that won’t take no for an answer.
However, with the weight of a nation resting on his shoulders, Tiafoe has always been focused on making his parents proud.
“With them trying so hard, I felt like I didn’t want to let them down,” he told CNN Sport in 2015. “I felt like I didn’t want to leave the opportunities for granted.”
CNN’s Will Edmonds and Christina Macfarlane contributed reporting.