Watch: Roger Federer keeps his promise to young kid who asked him why he is called the GOAT

Sometime in June this year, Roger Federer treated one of his biggest fans in the world to the best news: playing a game of tennis with him and keeping a long-standing promise in the process.

At the 2017 US Open, Izyan Ahmad delighted the 20-time Grand Slam champion by asking him why he was called the GOAT when Switzerland did not have a plethora of livestock. Ahmad, nicknamed "Zizou," went on to request that the Swiss play for a few more years, so that one day he could play against him as a professional.

Five years later, Federer is yet to retire, while Ahmad is a standout player on the juniors tour. The 11-year-old became the No. 1 player in both singles and doubles in the US earlier this year, and looks well on track to make it onto the ATP tour in the years to come.

Meanwhile, Italian food company Barilla wanted to fulfill Zizou's dream before the 41-year-old hung up his raquet. In a video they shot through hidden cameras and microphones unbeknownst to Ahmad during his training in Zurich a couple of months back, the company tricked him into meeting with the former World No. 1.

At a restaurant Ahmad and his coach went to dine in, one of the waiters was tasked with telling the 11-year-old that the owner of the location was a huge fan of his and wanted to take a selfie with him.

Posing as the owner, a lady wearing a t-shirt with his face on it soon arrived to be photographed alongside Zizou, sending the kid into an embarrassed confusion. All this was being monitored by Federer in the background, who found it extremely funny to see the 11-year-old's legs being pulled.

Moments later, the crowd near the restaurant started chanting Ahmad's name loudly while holding placards cheering him on. At this point, the waiter dragged him onto the tennis court and told him that the gathered fans wanted to see him play against a "worthy opponent."

This was the cue for Roger Federer to come out of hiding, and the 20-time Grand Slam champion's surprise entry totally caught young Ahmad unaware. After getting over the initial shock, Zizou came back to his senses and greeted the Swiss Maestro, muttering silently to himself that he could not believe this was really happening.

The 41-year-old then reminded him of his earlier promise and asked him if he was ready to play a quick match.

"We made a promise, right? We are going to play," he said. "You ready?"

Naturally, Ahmad answered in the affirmative and proceeded to match the former World No. 1 shot for shot. The duo exchanged a few exquisite shots, as Federer constantly peppered in words of advice and praise for the 11-year-old. To his credit, Zizou pulled off a tweener at one point that made the Swiss smile brightly.

The match eventually winded down to a close, but the scoreline was never revealed to the viewers. Instead, the closing shot of the video simply showed the pair in the process of wolfing down two plates of delicious pasta while not revealing who actually won.

Ahmad shared the video on his Twitter account today, thanking Federer for the "best day" of his life. He went on to wish the Swiss a very happy 41st birthday, adding that he continues to remain the GOAT in his opinion.

"When the GOAT makes a promise, he keeps it! That’s what makes him such an idol! Thank you Mr. Federer, for the best day of my life, for these memories and I am forever grateful that you kept your pinky promise!” HAPPY BIRTHDAY G.O.A.T!" Ahmad wrote.

Roger Federer will be back in action next month at the Laver Cup

Roger Federer will be back in action at the Laver Cup in September

As for his professional comeback, tennis fans will have to wait until next month to catch sight of Roger Federer once again. The former World No. 1 is slated to play at the Laver Cup in London, where he will be joined by the likes of Novak Djokovic, Rafael Nadal, Andy Murray and others as part of Team Europe.

Following his stint in the team competition, the Swiss Maestro will return home to play in the Swiss Indoors in Basel, an ATP 500 tournament he has won 10 times till date. Provided his performances in both events are satisfactory, the 20-time Grand Slam champion will look to play the full calendar in 2023.