The 24-year-old just stood there and soaked up the atmosphere created by a noisy Arthur Ashe Stadium.
It felt like a defining moment in the American’s career; 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 have long been high for Tiafoe and the world No. 26 now looks more than comfortable on the sport’s biggest stage.
Should Tiafoe reach the semi-finals on Wednesday by beating Andrey Rublev, he would record a career-best Grand Slam result and the performance will be all the more impressive given his humble beginnings.
After all, Tiafoe’s path to tennis was by no means traditional.
Her father, Constant Tiafoe, started working at the Junior Tennis Champions Center in Washington, DC in 1999 and eventually moved into one of the vacant storage rooms while he worked around the clock.
His two boys sometimes stayed with him and slept on a massage table while their mother worked night shifts as a nurse.
The unusual entry into the sport gave Tiafoe the opportunity to begin developing his skills, and once he began training at the facility he has not looked back.
Fueled by his parents’ work ethic, he won the prestigious Orange Bowl – one of the most prized junior tournaments in tennis – at age 15, becoming the youngest boys’ singles champion in the tournament’s history.
He joined a list of previous champions including Roger Federer, Andy Roddick, Ivan Lendl, Jim Courier, John McEnroe and Bjorn Borg.
It was a sign for the future.
Matured on tour
Tiafoe turned pro in 2015 and began to adapt to the rigors of the senior tour.
He broke into the top 100 in the world and started to assert himself in Grand Slams – at the Australian Open in 2019 he reached his first quarterfinal before losing to Nadal.
Three years later he finds himself in another quarter-final, only this time he feels more ready to seize the opportunity.
“Honestly, when I first came on stage, I wasn’t mentally ready and mature enough,” he said on the pitch after beating Nadal. “I was able to develop further and I have a great team around me.
“I’m glad I won in front of my mum, dad, girlfriend and my team and that they see what I’ve done.”
As he solidifies as a contender on the court, Tiafoe also strives for social justice outside of the court.
In 2022, he told CNN Sport that the lack of diversity in sport made him feel like an “outsider,” and he vowed to keep fighting for equality while he still had the platform.
He created a protest video in 2022 to raise awareness of racial injustice after the death of George Floyd sparked protests around the world.
In collaboration with a variety of black players and coaches – such as Serena Williams and Coco Gauff – he released the video “Racquets down, hands up” on his social media channels.
On the pitch, his next match against Rublev will surely be the biggest of his career so far.
The home crowd will be hoping his hero can keep reaching new heights in his bid to win a first Grand Slam title.
His performances have even caught the eye of some of the biggest names in esports, with NBA star LeBron congratulating James Tiafoe on making it to the quarterfinals.
Make no mistake, however, this is not an overnight success story. It’s the result of thousands of hours of work and a no-no mentality.
But while the weight of a nation rests on his shoulders, Tiafoe has always focused only on making his parents proud.
“Since they were 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 take the possibilities for granted.”
CNN’s Will Edmonds and Christina Macfarlane contributed coverage.