Moody (20), a physical education student at the University of Otago, was always in command and won the 1500m in 4min 2.82sec.
He had a commanding lead at the bell and put daylight between himself and the rest of the field when he ran the last lap in 64sec.
Moody had a medical scare nearly three years ago, when he suffered from a hole in the lung while a pupil at Bayfield High School.
It was not life-threatening and healed itself.
Moody has not had any recurrence of the problem and proved his fitness 18 months ago when he set an Otago record for an 18-year-old of 3min 51.20sec to break the 1500m record that was held by fellow Ariki club member Max Smith, who is now on a running scholarship in the United States.
Another notable performance in the 1500m on Saturday came from Bryce Morgan (Ariki) who finished with a strong burst to capture second place in 4min 13.17sec.
Morgan (17), a pupil at Otago Boys High School, was in fifth place in the back straight but his fast last lap of 65sec saw him squeeze past Daniel Balchin (Caversham) on the line.
Balchin ran 4min 13.42sec.
Morgan needed a fast time to convince the Otago Boys selectors that he deserves to be in the school team for the New Zealand secondary schools athletics championships at Hamilton in December.
Christina Taylor (16), one of 20 Southland athletes competing at the meeting, took the lead in the women's 1500m after two laps and won in 4min 52.29sec.
Hill City's Rebeka Greene (15) clung closely over the last two laps to finished second in 4min 54.6sec.
It was a personal best time by 5sec for Greene, who is a late selection in the New Zealand team for the Pacific Schools Games in Canberra in December.
Rebecca Gibson (Southland) won the women's aged 17 to 19 100m in 12.73sec and the 400m in 62.1sec.
The best performance in the jumps came from Southland's Ben Graham (17) who won the men's aged 17 to 19 high jump with 1.75m and the long jump with 5.79m.
Another Southland athlete Greer Alsop (14) had the best women's long jump of the day with 5.6m.
Thirteen athletes travelled from Timaru for the meeting, held in bitterly cold and wet weather.
Probably the best South Canterbury performance came in the 3000m race walk from two athletes who are competing in the Pacific Schools Games.
Lucinda Shaw (15) won the women's event in 17min 35.42sec and Daniel Lord (17) the men's race in 14min 24.46sec.
