By the time she was 5 months old, baby Jhia Rolleston had been punched, thrown and shaken by her mother's partner.
Polash Kabhir pleaded guilty to causing grievous bodily harm with reckless disregard to the child when he appeared in the High Court at Auckland today.
His lawyer Hugh Leabourn asked for Kabhir to be remanded on bail until sentencing in August.
Mr Leabourn said Kabhir had always turned up to court, was abiding by his curfew and was living with his father.
But Justice Mark Cooper said he was not prepared to grant bail for the serious charge Kabhir had admitted to.
The Crown says Kabhir punched baby Jhia, shook her, threw her and put his hand over her mouth.
Kabhir stood trial last year. The jury acquitted him on one charge but could not decide on the serious charge of causing grievous bodily harm.
The Crown had sought a retrial but this morning's plea will mean that will not be necessary.
At his trial in November, the High Court jury were shown X-rays of baby Jhia which showed the abuse caused bleeding on her brain.
She also had broken arms, legs and ribs.
Crown prosecutor Sam Wimsett told the jurors that Kabhir had thrown the baby at her cot, shaken her and on more than one occasion punched her.
"What the Crown says is there is more than one act of violence against Jhia."
Starship Hospital radiologist Dr Russell Metcalfe took the jurors through a series of X-rays taken in October 2010.
The images showed broken bones in the child's legs and arms. She also had a 7cm fracture in her skull.
"That is quite a lot in a little infant. A baby's head is a lot smaller than ours. It would actually be impressive if you had a 7cm fracture in an adult."
Dr Metcalfe said seven of Jhia's ribs had also been broken in the previous three weeks.
He said the force required to break Jhia's ribs would be comparable to a high-speed car crash or a fall from a great height.
"Even from those [incidents], we don't see rib fractures."
He said he believed Jhia had been picked up and "squeezed quite forcibly".