Sydney man jailed for glassing guard

A drunk Sydney man who glassed a 63-year-old security guard in the head and ran away has been jailed for at least two years and four months.

Pituodemongtero Ung was asked to leave a Cabramatta restaurant on a Saturday night in October 2015 when he attacked the security guard, leaving him with deep cuts to his neck.

Ung, who pleaded guilty to wounding a person with intent to cause grievous bodily harm, was sentenced at Campbelltown District Court on Thursday.

Justice Antony Townsden noted Ung was moderately intoxicated and attacked a person in a "vulnerable position".

The court heard when security asked Ung to leave the restaurant for pushing a woman's chair, he picked up a glass from a table and hit a guard in the head and face three times.

He then ran off while the guard was held back by patrons.

The guard was rushed to hospital for emergency surgery but suffered no permanent injury.

Ung, who moved from Cambodia to Australia in 2009, appeared remorseful and told the court he now doesn't drink aside from the occasional beer at home.

"I feel very sorry for the man, I never intended to do it," he said.

Ung should be eligible for parole in June 2019 with Justice Townsden referring to his previously clean record and his good chance of rehabilitation.