He felt betrayed that his good friend had told his wife he was having an affair. In a fit of anger, the 23-year-old man slashed his friend on the face, leaving the 24-year-old victim with a 7cm-long scar on his left temple and nerve injuries.

Yesterday, Jeremy Chong Jia Jian, who is unemployed, was sentenced to three years' jail and four strokes of the cane after pleading guilty to one count of voluntarily causing grievous hurt.

Another charge was taken into consideration.

Chong and the victim, Mr Scott Seo Chit Seng, were close friends from secondary school.

The pair met regularly until November last year, when Chong learnt that Mr Seo had told his wife he had an affair.

In a letter written to the judge, Mr Seo said he did so out of "anger and jealousy" as Chong had been flirting with a girl, whom he was interested in.

On Jan 13, Chong arranged to meet Mr Seo in Punggol Park at night and they decided to end their friendship. Before they parted ways, Chong warned Mr Seo to "watch out".

Later, at about 2.20am, Mr Seo was having supper with three friends at a coffee shop in Block 266, Compassvale Bow, when Chong - holding a fruit knife - approached the group.

He was furious that the two mutual friends, along with Mr Seo, had left their shared WhatsApp chat group.

Chong first pointed the knife at one of his friend's neck. The confrontation turned violent when Mr Seo tried to intervene by pushing Chong away. Chong then slashed the left side of Mr Seo's face once causing a deep gash and severing two facial nerves.

Several punches were thrown among the friends, with one smashing a beer bottle against a pillar to threaten Chong.

In the scuffle, Chong also slashed 19-year-old Ang Rong Jun on his face, leaving a 12cm-long scar.

Chong then drove off from the scene to his girlfriend's home. He disposed of the blood-stained knife along the way.

In mitigation, Chong's lawyer, Mr Lee Ah Fong, asked for a shorter jail sentence and no caning.

He said Chong was sorry for his actions and had offered to give Mr Seo $6,500 as compensation for his medical fees, which Mr Seo had accepted.

Furthermore, Chong has a 1 1/2- year-old son with his wife, who is a stay-at-home mum. Chong added in a letter to the judge: "I wish to give my son a complete family."

However, the judge noted that Chong was "clearly the aggressor" and his anger was "no justification for the ferocity of the attack".