A Hawke's Bay teenager has been found guilty of murdering Haumoana man Mark Geoffrey Beale.

Johnnie Puna, 19, murdered 45-year-old Beale who was found near the Tukituki River mouth with unsurvivable brain injuries on Waitangi Day and later died in hospital.

The unanimous verdict comes after three hours of deliberations in the High Court at Napier this morning.

Puna attacked Beale just hours after meeting him in a chance encounter on Haumoana beach in February this year.

The pair, who were sharing Beale's home brew vodka, were returning from Beale's home with more alcohol when the Haumoana man accidentally fell and pulled Puna down with him.

The 19-year-old was angered and repeatedly kicked Beale in the head, knocking him out before waiting for him to wake up before continuing the assault.

Mr Manning began his closing submissions on Thursday morning by asking the 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 fully forced kicks 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, that 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.