Jake Paul just took down another former boxing champ ... defeating Julio Cesar Chavez Jr. by unanimous decision on Saturday.
The crowd at the Honda Center in Anaheim was overwhelmingly in support of 39-year-old Chavez Jr -- but for the most part, they didn't get the show they were hoping for.
The early rounds easily belonged to 28-year-old Paul ... with Chavez Jr. hardly throwing -- let alone landing -- any punches, to the point where the fans started to voice their disproval.