But the girl had a severe reaction and collapsed unconscious.
Fellow park users then saw Rutledge putting a hand up her skirt, touching the girl's upper thigh.
They rushed to her aid, where the unemployed man told them, "This is not right," and to ring an ambulance.
The next thing the girl remembered was being in hospital. She was unwell for a couple of days.
She later described her reaction to the drug, saying she couldn't talk or move her limbs and felt sick and dizzy.
Rutledge was arrested that day, September 18 last year, and originally charged with wilfully and without lawful justification or excuse stupefying the girl in Woodham Park and indecently assaulting her.
Police later dropped the stupefying charge and stuck with the indecent assault count, which he pleaded guilty to.
Today at Christchurch District, Judge Jane Farish accepted the man's remorse as genuine and sentenced him to 200 hours of community work, and to undertake 12 months of intensive supervision.
She also ordered him not to take non-prescription drugs, including herbal tobacco, which she said she was having to deal with every day, with people appearing in the dock having got into trouble while under the influence of "horrible" synthetic drugs.
Defence counsel Clare Yardley said Rutledge was an "unsophisticated person" who was still troubled by the distress he caused the young girl.
Since the incident, he had vowed to give up smoking the drugs, even though "he finds it relaxing".
The girl had learned important lessons about the so-called herbal drugs, Judge Farish said, and hoped she passed the message onto her friends and peers.
"It is causing huge problems for us as a city," the judge said.
