The 19-year-old was angered and repeatedly kicked Beale in the head, knocking him out. He then waited for him to wake up before continuing the assault.
Manning askedthe jury to put themselves in Puna's bloodied shoes and walk around in them.
"Put yourself in Mr Puna's place and ask yourself what else can he have been thinking. What was he thinking as he drove, forcefully, his foot into the face and head, repeatedly, of a defenceless man lying on the ground?"
During three days of evidence the jury heard Puna delivered 13 full-forcekicks to the Haumoana man's head before urinating on him.
Defence lawyer Eric Forster told the jury there was no doubt what Puna did to Beale was terrible, but that the appropriate verdict would be manslaughter.
However the jury's verdict meant they agreed with the Crown, which argued the defendant either intended to end Beale's life, or intended to cause bodily injury he knew was likely to cause death and did so anyway.
Puna earlier pleaded guilty to stealing the dead man's cellphone and vaping device.
He was convicted and remanded in custody for sentencing on February 8 next year.
