Ja'Marr Chase might be the son of the decade ... 'cause the Bengals star just revealed he got his mom a new car and paid off her house with the first million dollars of his rookie contract.
The wide receiver got into details on how he spent a milli from his $19.8 million signing bonus on GQ Sports ... saying his first purchase was a $65k black Maserati for his mom, Toeleah, to replace her Audi that was in bad shape.
"The air stopped working in it, so she's not about to try to ride around in no hot car.