Actually, NY Yankees star Aaron Judge is murdering sales records for a shirt company -- after he rocked a 'Sandlot' inspired button-up ... and they started flying off the shelves.

After the Yanks beat the Orioles on Saturday, Judge sported "The Great Hambino" shirt to address the media in the locker room ... and people went crazy for his outfit.

In fact, we spoke with the owner of the clothing company, RSVLTS, who tells us Sunday was the company's best sales day ever -- they sold more than TWICE as many shirts as usual (and usual is 100s of units).

Long story short ... Judge is just as hot in the fashion world as he is at the plate.