Father-of-three Pirini had brought Leaf to Napier to meet his mother during what defence counsel Amit Malik referred to as a "whirlwind romance".
Their vehicle was stopped by Mr Daly in a side street in Clive in relation to thefts.
The attack started when Pirini, having surrendered the keys after being stopped, punched the officer without warning.
Mr Daly fell to the ground and when he got up, Leaf got out of the car, smashed the officer's radio so that he couldn't call for assistance, and stomped on his eye.
Pirini grappled with the officer on the ground, punching him in the head, and the attack stopped only when residents came to the aid of their community's long-serving and respected constable.
One of the residents, Robin Oliver, this month received a Royal Humane Society Certificate of Merit recognising his bravery.
Mr Daly had three operations on his eye socket, and was placed on life-support in hospital after almost dying from an adverse reaction to an anaesthetic. He was off work for six months, and has found it impossible to train for what had been an active sporting lifestyle.
Justice Forrest Miller said it was clear Leaf stomped on the prone officer and caused the major eye injury, which was likely to affect him for the rest of his life, while Pirini's punch and struggle with the officer on the ground caused only abrasions and bruises.
The judge used the maximum possible penalty as the starting point for calculating the sentence, and deducted 10 months to recognise the lack of previous serious offending.
But Justice Miller then added three months for the three thefts that had preceded the attack.
Justice Miller warned Mr Malik he took "a very, very dim view of your client," and, commenting on Pirini's assault on Mr Daly on the ground, said: "It's inescapable that he knew (Ms Leaf) had kicked him in the head."
"This offending was completely unprovoked and without warning, and were it open to me I would impose a significantly longer sentence than I am able to do," Justice Miller said.
The judge said the pair had travelled from Auckland, topping up the tank in Taupo and driving away without paying for more than $70 worth of petrol. Pirini also stole a $149.90 pair of shoes in Napier, and on the day of the attack filched bread, milk and cigarettes from Arkwright's Corner Store in Napier. Leaf was waiting at the wheel to drive towards Clive, when Mr Daly intervened.
Pirini had been in custody since, and Justice Miller said the total of two years and five months in prison would be cumulative to a nine-month sentence imposed while on remand for previous offending.