Green, 39, last year lost the belt to Antonio Tarver but the American was stripped of the title for doping.
Green was simply too good for his Kiwi opponent in front of a sold out crowd last night Australian time.
The judges cards read 119-109, 116-112 and 116-113, convincingly in Green’s favour, leaving his career record at 33-5 after 11 years in the ring.
Cameron, a natural heavyweight who had to drop 8kg to make weight, was gallant and could have become the first Kiwi-born pro in more than 100 years to win a world title.
Green was prepared to spend the fight on the inside of his bigger opponent and the tactic paid dividends.
“I knew if I needed to work inside I could work inside and I out-muscled a much bigger man,” Green said. “I’m so happy and very, very proud to have won.”
Dodging speculation that he would retire after the fight he said: “I’m going to be an Aussie and get on the cans with the boys.”
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