The County Court in Ballarat heard William Matai, 32, of Cooranbong in New South Wales, was working at The Bended Elbow when he assaulted the "vulnerable" 22-year-old woman on July 19, 2007.

The married father of two entered the toilet cubicle about 5.30am where the woman was bent over the toilet vomiting.

The court heard Matai was in the cubicle with the woman for about 10 minutes where he kissed her face and tried to lift her dress up while saying "come on baby".

He grabbed the woman's hair, pulled her head aggressively and she hit it against the wall, before he unzipped his pants.

Crown Prosecutor Barry Schultz said the woman was choking and gasping for air and pleaded for Matai to leave her alone because she was not feeling well.

He said Matai denied the events saying that the woman asked him to have sex with her but she refused.

The court heard the woman had suffered neck problems, fear and anxiety after the incident.

Defence Barrister Stephen Howe said before the assault, his client had stayed for "knock-off" drinks at the hotel and he was "quite drunk".

"He had some expectation that his overtures may be received but they were not. At that point he should have resisted but he didn't," Mr Howe said.

"He didn't go into that toilet cubicle with the intention of indecent assaulting."

Mr Howe said Matai was born in New Zealand and raised in the Seventh-day Adventist Church. He said Matai was enrolled in theological studies to become a minister and help other people.

Judge Jane Patrick described the assault disgusting on a vulnerable person.

"I expect this behaviour was out of character for you and that you were drunk," Judge Patrick said.

Matai was sentenced to 15 months' jail, suspended for two years after pleading guilty to one count of indecent assault.