PWCC officials tell TMZ Sports they brokered the historic sale Thursday night ... and say the card's exclusivity -- it's the only one that exists -- is why it sold for so much.

"This is arguably the best WWE trading card in existence," said Jesse Craig, Vice President of Sales at PWCC. "Cards like this rarely surface for public sale since they are so scarce. And when scarcity outweighs public demand, you see record prices."

"This was the perfect combination to drive that demand," Craig added.

The card is considered a 1/1 masterpiece with a grade of Near Mint 7. It features a holofoil image of The Rock -- AKA "The Great One" -- slamming the Texas Rattlesnake, "Stone Cold" Steve Austin, to the mat with what appears to be his signature "Rock Bottom" finisher.

Of course, The Rock and Stone Cold had one of the most storied rivalries in WWE history, culminating in a trilogy of matches that were instant classics at WrestleMania 15, 17, and 19.

When Rock and Austin weren't colliding in the squared circle on "The Grandest Stage of Them All," the two WWE Hall of Famers entertained the WWE Universe with their skills on the microphone, cutting some of the most legendary promos over their careers.

Both Rock and Austin have had successful careers post-WWE -- Dwayne is an A-list actor, and Steve Austin started a podcast and released his first beer (Broken Skull) -- but the magic the two created inside the ring shows why cards like these are in high demand.