The happiest person at the French Open on Sunday might not have been the newly crowned men's champion.

A young fan displayed even more jubilance than Novak Djokovic after receiving a one-of-a-kind souvenir.

Moments after rallying from a two-set deficit to defeat Stefanos Tsitsipas and secure his 19th major title, Djokovic generously gifted his match-used racket to a boy in the first row of the stands. The boy clutched the racket with both hands and jumped up and down in a mixture of elation and disbelief.

Asked about the heartwarming moment after the match, Djokovic explained that the boy had remained in his corner when he appeared destined to lose, encouraging him and even offering some suggestions.

He was like: ‘Hold your serve. Get an easy first ball and then dictate. Go to his backhand,'" Djokovic told reporters with a laugh. He was coaching me, literally, and I found that very cute and very nice. To give the racket to the best person — it was him — after the match. That was kind of my gratitude for him sticking with me and supporting me.”

Sports memorabilia experts told Yahoo Sports the boy had good reason to be excited about the gift. Djokovic's racket would be worth tens of thousands of dollars if the boy put it up for auction.

The racket could fetch between $25,000 and $35,000 today, estimated Ken Goldin, founder and executive chairman of Goldin Auctions. Ezra Levine, CEO of the sports memorabilia investment platform Collectible, went even higher, calling more than $50,000 a "conservative estimate."

Both Goldin and Levine told Yahoo Sports the racket could appreciate quickly with Djokovic within one major title of tying Roger Federer and Rafael Nadal for most all-time by a male player. Goldin valued the racket at $50,000 if Djokovic secures 20 or more major titles and $75,000-$100,000 if he wins this year's Wimbledon and U.S. Open to complete a 2021 grand slam.

While Djokovic's French Open racket is a lucrative souvenir for tennis, it's nowhere close to the value of a comparable item from a more popular sport. For example, Goldin says Tom Brady's game-worn 2021 Super Bowl jersey could fetch more than $1 million.

Of course none of this may matter to the boy who received Djokovic's racket. Judging from his reaction, he may not be looking to sell anytime soon. To him, that piece of tennis history may be priceless.

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