Poi suffered permanent brain injuries and multiple fractures, and was confined to a wheelchair, unable to speak or to use his arms or legs.
Leota, now 35, denied the assault but a jury found him guilty on a charge of intentionally causing grievous bodily harm, which carried a maximum sentence of 14 years.
The Crown successfully sought preventive detention because of the offender's history of violent crime and the risk for public safety.
The sentence was for an indefinite term, with stringent assessment requirements before the offender could be considered for release.
Leota claimed sentencing judge Justice Karen Clark did not place sufficient weight on a health assessor's report and failed to consider the possibility of an extended supervision order being put in place after a sentence such as the 11 years which Leota sought in the appeal, and which would have been served in full as stage two of the three strikes regime.
Justice Mark Woolford said Leota had been warned at his earlier sentencing in 2013 of the possibility of preventive detention. His victim on that occasion would not have survived had surgeons been unable to remove a bone fragment from his brain.
Leota was told by Justice Timothy Brewer at that time he "should be in no doubt whatsoever that if there is further offending it is most unlikely that a judge would decide that preventive detention was not the best option for you".
Justice Woolford said: "In our view, the judge was entitled to conclude that a sentence of preventive detention would incentivise Mr Leota to change. With a sentence of preventive detention Mr Leota knows that he will stay in prison unless he changes."
"Mr Leota has nearly killed two men in separate episodes of violence," Justice Woolford wrote.
"He has an extensive history of violence. His violence appears to be purposeful rather than initiated by a loss of control."
"The judge was entitled to conclude that Mr Leota posed a significant and ongoing risk to the safety of the public," he said.
