Domata Peko Says Father-In-Law Who Sold Lotto Winner Gifted Grandkids $100k

The guy who got a million bucks for selling the record-breaking Powerball ticket didn't spend the dough on a new car or a fancy vacation ... so says his son-in-law, ex-NFL star Domata Peko, who tells TMZ Sports he gave $100k to his grandkids instead!!

Joe Chahayed -- who owns the Joe's Service Center gas station in Altadena, CA -- was the man of the hour in November ... after it was announced his shop sold the $2 BILLION ticket.

We spoke with 38-year-old Peko about Joe's million-dollar payday ... and he says it really wasn't so life-changing, 'cause he's still grinding every day at work!!

"That's the one thing about him, he's one of the hardest workers I know," Peko said. "He's been working forever. And even though he won and got that quick little million, he's still grinding, bro."

The former Cincinnati Bengals nose tackle says Chahayed didn't ball out with his winnings, but set his grandchildren up with an amazing financial gift.

"I'm like, 'hell yeah,' that's the type of person he is, man," Peko said. "He loves to give back. And that's why I think God keeps blessing him, man, because he loves to give."

As it turns out, good karma might be heading Chahayed's way ... 'cause Peko says he heard the person who won -- a man named Edwin Castro, who reportedly collected the prize as a lump sum of $997.6 million -- wants to give Joe a nice "thank you" gift!!

Peko also said there's now a line out Chahayed's door every time there's a huge drawing ... with customers hoping luck strikes again at his station.

Of course, a lawsuit was filed as a result of the lotto ... with a guy named Jose Rivera claiming he was the real winner, but his ticket was stolen.