A jury has begun deliberating in the case of a man accused of knocking another man unconscious outside a southside bar.

Mathew Neish is on trial in the ACT Supreme Court, having pleaded not guilty to recklessly inflicting grievous bodily harm. Neish, 26, is accused of attacking the man outside the Soul Bar in Woden in October 2010.

Both legal teams completed final submissions on Tuesday, with the Crown saying Neish was the aggressor in the incident.

But the accused man's barrister argued his client had acted in self-defence.

There is no dispute an incident occurred outside the venue, leaving the alleged victim with two black eyes and a fractured eye socket.

The jury heard the alleged victim had been drinking with his girlfriend at the bar when he went to buy cigarettes about 11pm.

While away, Neish made comments of a sexual nature to a number of women.

The alleged victim's girlfriend became upset and confronted the accused man's partner.

When the alleged victim returned, he saw his girlfriend inside the bar arguing with another person.

The man said Neish then left the establishment and accosted him, shouting: ''Go sort that bitch out.''

The complainant said he started moving backwards when he was punched in the head without warning.

The alleged victim told the court he covered his head with his arms and said, ''I don't want to fight you'', but Neish continued to hit him another five times.

He said everything went black and he fell to the ground where he was struck a further four times before he lost consciousness.

But the defence argued Neish had struck the complainant in self-defence, after the man grabbed him by the collar and swung an arm.

Neish told the court the pair then stumbled and fell to the ground where they were separated soon after.

Justice Richard Refshauge on Tuesday gave jurors final directions before sending them to deliberate.

The deliberations continue on Wednesday.