Master P is challenging YG to an NFL version of big bank take lil' bank ... telling TMZ Sports he's so confident his New Orleans Saints will beat YG's Rams this weekend, he wants to put $40K on it.
We got P out in L.A. on Monday ... and he was still on a high from the Saints beating the Eagles and punching their ticket back to the NFC title game for the first time in nearly a decade.
Of course, YG is a massive L.A. Rams fan -- and when P heard the rapper won $20k in an NFL playoff bet with Dallas Cowboys super fan Post Malone, the No Limit boss had to up the ante.