Andre Agassi and Steffi Graf are proving to be ambassadors of not just Longines, but of humanity as a whole

You've heard the story; it is the sports fairytale to beat all sports fairytales.

Andre Agassi and Steffi Graf are two of the greatest tennis players that ever lived, two athletes who repeatedly stunned the world with their otherworldly on-court brilliance, two individuals who gave new meaning to the word 'champion', two personalities who are the epitome of style (in the case of Agassi) and grace (in the case of Graf). They were also, before Rafael Nadal and Serena Williams came along, the only two players in history to have completed the Career Golden Slam (that's winning all the four Majors plus the Olympic singles gold).

How improbable then, how absolutely, indescribably magical, that they would end up married to each other?

It didn't happen by chance, of course. As Agassi details with delightful alacrity in his book Open, back in 1999 he did everything in his power to help Graf take note of his charms. There were a few stumbling blocks along the way, but their courtship soon captivated the entire world, and culminated in a happy marriage that is still going strong today.

Graf retired in 1999, Agassi in 2006. But their contribution to the tennis world, and to humanity at large, hasn't stopped.

Agassi and Graf are both ambassadors of luxury Swiss watchmaker Longines, and they make regular public appearances for the brand - as they did during the Longines Future Tennis Aces final held at the Eiffel Tower last week.

Steffi Graf and Andre Agassi in action during the exhibition match at the Eiffel Tower

The two played a cute little exhibition match with boys' and girls' winners of the U13 tournament, and it would be an understatement to say that the large crowd gathered at the court was absolutely enthralled.

Agassi and Graf have two kids of their own, which is why it wasn't surprising that they were both so comfortable interacting with all the junior players assembled on the court. They kept voicing words of encouragement, both during the exhibition match and later during the photoshoot, and you could see that the kids were completely in awe of the two legends.

Agassi and Graf with the U13 players, along with Alex Corretja and Arantxa Sanchez-Vicario

But more importantly, their appearance also highlighted the charity work they've been doing with their respective foundations - charity work that is being supported and encouraged by Longines.

Agassi set up The Andre Agassi Foundation in 1994, an organization that seeks to help provide educational opportunities to the Las Vegas youth. As a Vegas kid, Agassi himself didn't have the best of opportunities growing up; this is his way of ensuring that others can have what he didn't.

Graf on the other hand has adopted a more global approach in her endeavors. She is the founder of "Children for Tomorrow", a charity that provides assistance to families that have been affected by war, violence and exile.

Both the organizations have already helped countless individuals, children in particular, all over the world. And both the organizations will continue doing so for many years to come, considering how hands-on and involved Agassi and Graf are.

At the gala dinner held at the Musee Rodin after the conclusion of the Longines Future Aces, Agassi spoke at length about how much his foundation means to him, and how thankful he is to Longines and all the other patrons who are helping him provide a better future for underprivileged kids. Graf on her part didn't speak much, but when has she ever? As always, she let her actions speak louder than her words - and her body of work with Children for Tomorrow screams out pretty loudly.

Agassi and Graf spent close to two decades wowing the world with their tennis skills. Now, two decades after their retirement, they look like a picture of domestic bliss - he the aging but still bad-ass rockstar, she the beautiful and elegant lady - and the two of them together helping future generations of tennis players with their advice and encouragement.

But make no mistake, their contribution to the world goes a lot deeper than that. By putting their charity organizations front and center of everything that they do, Agassi and Graf are helping make a better tomorrow.

If ever there had to be a pair of ambassadors for humanity, Andre Agassi and Steffi Graf would be prime candidates.