Timothy Ralston remembers yelling to Digby Gram "you've hurt him, you've hurt him, just leave him alone, he's out cold'' as his mate, Rhys Marshall, lay unconscious in Police Lane in the early hours of May 10.

Mr Marshall, 21, died at The Alfred Hospital in Melbourne from serious head injuries five days after the alleged assault.

Mr Ralston told a committal hearing at the Ballarat Magistrates' Court yesterday that he watched Gram stand over Mr Marshall after he had punched him, and cock his arm as though he was going to hit him again.

"When he first hit the ground he went over the top of Rhys, then took a few steps back. It looked like he went to punch him again,'' he said.

Gram, 20, of Ballarat, has been charged with one count of manslaughter.

Mr Ralston told the court he and Mr Marshall were walking from JD's Sports Bar to the Karova Lounge when they first noticed Gram lying on the ground in Police Lane.

He said when the pair approached to help, Gram stood up and began yelling and headbutting a verandah post.

"When he spoke he was very aggressive so we stopped and backed away,'' Mr Ralston said.

He said Gram took a few quick steps towards Mr Marshall and hit him causing him to fall and hit his head on concrete.

Mr Ralston told the court he feared Gram was going to hit his friend again while he lay unconscious on the ground.

Gram's former girlfriend, Jennifer Nolan, told the court she met up with a drunken Gram at Haida Bar where she told him he needed to sober up.

She said the pair left the nightspot 30 minutes later and crossed Camp St to talk about their relationship when he started headbutting the post and she became "very worried".

Ms Nolan said Gram eventually stopped and was swaying and appeared to be out of it, before Mr Ralston and Mr Marshall approached.

Earlier, the court was told Mr Marshall had been drinking at a friend's house, before going to a trivia night at Buninyong and then Zagames on the night of the alleged assault.

While at the trivia night, Mr Marshall took part in a dance competition where he performed a somersault off a table.

The court was told there had been a rumour that Mr Marshall hit his head while performing this trick, but witnesses rejected the claim.

The hearing before Magistrate Kay Robertson continues today.