"I saw the old guy trying to wrap the chain of the dog around a branch and the other girl had a pan of water at that stage, and was trying to throw water on the dog and bash it with the pan."
The "other girl" was an 18-year-old, who had been walking past on her way to netball practice and rushed in to help when she saw the man in trouble.
"He'd already been quite badly injured, and the dog wasn't letting go.
"He had a pretty big gash on one of his legs and pretty much from his elbows down were just covered in blood," said Ms Rance.
In spite of his injuries, the man managed to wrap the chain of the dog around the branch and fend off the dog while freeing himself, she said. "He did amazing."
She also praised the efforts of the teen who narrowly avoided injury after stepping in to help, with little concern for her own safety.
Ms Rance called emergency services, and while waiting for them to arrive the pair bandaged the man's arms and leg. He was in shock, pale and sweaty, she said.
Police arrived shortly afterwards, and the man was later airlifted to hospital by Nelson Marlborough Rescue Helicopter.
He had no trouble conveying his feelings over the attack, she said.
"When police asked him how he was feeling, he was like 'p***ed off'."
Ms Rance said the dog was normally chained up, and because of that there had not been any previous concerns about safety around it.
Only the owner's teenage daughter was home at the time of the attack, she said.
The dog has been destroyed.
The animal was seized by dog control on Wednesday night, and would usually only be put down before court proceedings if the owner agreed to it, said a police spokeswoman. She confirmed the dog was destroyed yesterday.
