When they went to take photos of her injuries in the bathroom, the man said he heard the glass pane on his front door smash.
"Then it turned to custard," the man told the jury on Tuesday.
On the way to investigate, he picked up a piece of wood he had lying around but had no chance to use it. He entered the foyer of his home, "and whack", he said,
The witness told the court he caught a glimpse of Ferguson before two blows with a metal softball bat to his head sent him to the ground.
"People have probably seen seals clubbed. That's how I was clubbed, twice in three or four seconds," he said.
"My head burst like a balloon."
The man said he crawled to the sanctuary of his bedroom but Ferguson followed, ranting about the man having an affair with his partner.
He lost count of the number of times he was hit, he said,
"Both knees, legs, upper arms, ribcage - I just copped it," the complainant said. "All I was doing was trying to stay alive."
The man told the jury that Ferguson then changed his style of attack - allegedly using the butt of the weapon to ram him as he curled up in the foetal position.
Once the defendant relented and left the home, the bloodied complainant said he went into "survival mode".
"I got up off the floor because there was no way I was going to lay on the floor and die," he said.
He called emergency services and went outside, where he said he felt safer.
Defence counsel John Westgate suggested a different reason for staggering into the darkness on a broken foot.
The complainant was hiding a firearm from police, he said.
The man denied that was the case.
Westgate proposed an alternative version of events.
He said Ferguson had entered the address, accidentally smashing the window, and wrestled the wood off the resident after dodging a blow.
No metal bat had ever been found, Westgate stressed.
The lack of blood in the hallway, where the initial flashpoint allegedly took place, disproved the complainant's story, he told the jury.
Westgate said the man grabbed another piece of timber then went to his bedroom because he had a Glock pistol stashed under his bed.
Ferguson, he suggested, inflicted the blows because he knew of the weapon's existence and feared for his safety.
"The only way he could stop you was by hitting you with a piece of wood. He kept hitting you until you finally stopped," Westgate said.
"That's bulls***. That's lies," the complainant responded.
While spending a week in hospital recuperating, the man admitted Ferguson's partner visited him.
She gave evidence that the man told her he wanted to shoot Ferguson and was going for his weapon that night.
Under cross-examination, he firmly denied that conversation took place.
Her claims she had told Detective Mike Bracegirdle about the firearm just weeks before trial were rejected by the officer in charge of the case.
Ferguson has also pleaded not guilty to two charges of assault in a family relationship and one of strangulation against his partner, which allegedly took place earlier the same day.
The trial continues.
