Haney had defeated Kambosos via unanimous decision in June to add the WBA, IBF, WBO and The Ring belts to the WBC strap he already held and become the first undisputed champion at the weight since the start of the four-belt era.
The American produced another masterclass and received scores of 119-109, 118-110 and 118-110 from the three judges to seal the win on Sunday. He has now won all 29 of his fights, including 15 by knockout.
"I went in there and knew he was looking to the jab. We wanted to show some more tools in my arsenal. I think the right hand won the fight tonight," Haney said after handing Kambosos only the second defeat of his career.
"He is a warrior. I take my hat off to George Kambosos and all the Australians who came out."
Kambosos had previously suggested that he would hang up his gloves if he failed to win the rematch, but he said his latest defeat was not the end.
"I'm still a big, big name in the world of boxing. I hope you guys don't forget the 'Ferocious' Kambosos... I'll be back. There are still some big fights out there for me," Kambosos said.
"He's a great fighter. For me, to have the guts to go again with him. He gave me a good boxing lesson in the first round. He's a slick man. I gave my best.
"I tried my heart out. But this guy is going to be there for a long time. I gave him a great challenge. A great fight over 24 rounds. He's one of the best in the world in boxing, not just this division."
