He also told officers his son had acted as his sober driver many times before.
The man pleaded guilty to the charge in July in New Plymouth District Court.
At sentencing defence lawyer Jo Woodcock told the court the man has accepted he has some form of alcoholism, and has vowed to stop drinking.
She said the man has suffered a great deal of stress and shame following the incident, which was described as a terrible lapse in judgment.
The court heard the man is now with a new partner in a stable, healthy relationship, and hadn't seen his child since he was arrested.
Judge Philippa Cunningham said the incident was a gross breach of trust between a parent and their child, and that it caused potential harm to the man, his son, and other road users.
"It's a terrible lesson to give a child, that they are able to drive a car at age 10."
The court was told the man had previously faced drink driving charges, but Judge Cunningham said some good had come from the recent experience.
"You've found your drinking to be problematic," she said.
"If you didn't drink to excess you'd probably never have appeared before the court ever."
The judge said the starting point for the offending was 18 months' imprisonment, but acknowledged both Police and the defence see supervision and community work as sufficient to denounce and deter further offending.
The man was sentenced to 100 hours community work, 12 months' intensive supervision, disqualified from driving for 6 months, and was required to attend alcoholism and parenting programmes.