Chavez Jr. started aggressively, regularly lunging with mammoth right hooks, but Jacobs masterfully broke down his opposer's body from the second round with precise jabs.
Jacobs dominated the fifth round, giving Chavez a bloodied nose during a ferocious onslaught - the 33-year-old told officials before the sixth round commenced he was done for the night.
Chavez Sr. posted to Twitter in the aftermath confirming his son acquired a broken nose and requires surgery.
Incredibly, Chavez Jr. believes he did not lose the bout, suggesting Jacobs was firing illegal punches, as reported by DAZN reporter Chris Mannix.
"I was getting close but got headbutted above the left eye, then I had problems because of all the blood," Chavez Jr. said to Mannix.
"I came over to the corner and couldn't breathe. He elbowed me and headbutted me. Very tough fight I felt I couldn't go cause I couldn't breathe properly."
Jacobs was also unimpressed by Chavez's decision to quit in the fifth round, and sympathised with the disappointed crowd.
"He quit on his stool," Jacobs told Mannix.
"I'm from Brownsville - I never ran and I never will, but I'm going to duck these beer cans.
"I know they're not mad at me. They're mad at Chavez."
Jacobs dedicated the victory to late boxer Patrick Day, who passed away in October from brain trauma sustained in a knockout loss against Charles Conwell.