HE has all the attributes of a champion bullmastiff - gentleness, obedience, even compassion - and none of the negative behaviours often seen in ill-bred mastiff dogs.
Ace, at eight years old, is doing the gentlemanly thing and retiring from competition on a high note, having just won Best in Show and first Grand Champion at the National Specialty Show in Melbourne.
Ace's owner and devoted companion Melissa Smith lives with her husband Andrew near Lismore.
Their family of six dogs ("they're our children really, since we don't have kids", she says) has Ace as the patriarch, and comprises his half-sister, two daughters, and two grandchildren, some of which are showing the potential to become show winners.
Bullmastiffs are lucky to reach double figures and most have retired by the time they are five or six, Ms Smith said.
"In the past three years, since he was five, Ace has won everything he's been shown in," she said.
"We've always had a very strong bond.
"A couple of years ago I was diagnosed with cancer.
"For about two months before my diagnosis he started acting differently. He wouldn't let me out of his sight and wanted to sleep inside.
"I had to be in Brisbane from Monday to Friday for chemotherapy and felt really sick when I got home.
"He didn't make a big excitable fuss when I arrived home. He was very calm and just sat beside my bed the whole time.
"Now I hear about dogs that have diagnosed cancer and diabetes in their owners and I wonder whether he hadn't known about my cancer all along."
Originally bred to be gamekeepers' dogs, bullmastiffs were trained to see off poachers.
They would hurtle into the poacher's leg from behind, knocking him flat.
Then the dog would sit on its victim's chest, with its teeth at his neck, until the gamekeeper arrived.
These are heavy dogs - Ace tips the scales at 65kg.
The Smiths' dogs , when sold to new owners, come with a 40-page information booklet, and full paperwork.
"We won't sell to anyone who won't make a commitment to taking them to obedience classes and puppy school. Prospective buyers have to fill out a two-page questionnaire before I'll call them," Ms Smith said.
It's an expensive hobby.
The Smiths' vet bills alone come to about $15,000 a year and then there's the butcher's bill.
But she reckons it's all worthwhile, and that even Ace himself gets excited about his success.
"The more people clap, the more he loves it. You can't breed that into a dog," she said.
"The judges are amazed by his wonderful temperament; he's great around other dogs, puppies and children.
"He's my gorgeous 65kg lapdog.
"My husband calls him our golden child."