SINGAPORE - One minute they were merrily chatting away over bottles of beer, the next minute Tay Yang Leng started raining blows on his friend, causing Mr Yip Fok Weng, 58, to fall backwards and hit his head on a kerb.

The 61-year-old only stopped when he realised Mr Yip was bleeding profusely from his head and had stopped moving. He later died in hospital.

On Friday (May 11), Tay was jailed for 4½ years for causing grievous hurt to his friend.

The pair had consumed about 16 bottles of beer over seven hours at a coffee shop at nearby Block 803, King George's Avenue on June 27 last year.

It was an unplanned meeting. Deputy Public Prosecutor Goh Yi Ling said the two men had bumped into each other at around 4.40pm in a convenience store at Lavender MRT station and decided to catch up over some drinks.

They left the coffee shop at around midnight but then started arguing. Court documents did not state the reasons behind the row.

During the exchange, Tay forcefully pushed his friend who fell to the ground.

DPP Goh told District Judge Mathew Joseph that Tay then punched and kicked his friend multiple times, and continued hitting Mr Yip even after the victim fell down at least twice.

A 28-year-old woman, who was then walking her dog, saw Tay repeatedly punch Mr Yip's head.

She ran towards the men and told them to stop fighting but Tay told her that it was "just a friend thing".

DPP Goh said: "The witness then tried to separate the two men. However, the accused persisted in kicking and punching the victim. The witness saw that the final punch landed on the deceased's right cheek and caused him to fall backwards and hit his head against the kerb."

Mr Yip stopped moving after this. Tay then left in a taxi and the woman alerted the police. Officers arrested him on July 6 last year.

Mr Yip was already comatose when he arrived at Tan Tock Seng Hospital. He was admitted to the Neurological Intensive Care Unit and developed a high fever on July 20 that year.

He died of pneumonia the next day. An autopsy report revealed that he had suffered multiple injuries including fractures to his skull.

Pleading for the lightest possible sentence, Tay, who was not represented by a lawyer, told Judge Joseph that Mr Yip was a "nice man".

He told the court: "I know this is my karma...I will not drink again in the future."

Before handing out the sentence, the judge told Tay that he had committed a vicious attack and was "just a whisker away" from facing a charge that carries a capital sentence.

Judge Joseph added: "I find your conduct to be utterly reprehensible."

Offenders convicted of causing grievous hurt can be jailed for up to 10 years and fined or caned. Tay cannot be caned as he is over 50 years old.