Competing at the IAAF world junior athletics championships in Barcelona, Gill dominated the competition, recording a distance of 22.20 metres, just short if his personal best of 22.31 metres.
The Takapuna teenager retained the under-20 title he won two years ago in Moncton, Canada as a 15-year-old surprise package.
Gill's throwing was very consistent with five of his six throws good enough to win the competition; his series was 21.74, 22.19, 22.15, 21.84, 22.20 and 22.02.
Pole Krysztof Brzozowski was second with 21.78 metres while Australian Damien Birkinhead was third with 21.14 metres, with both athletes setting new national records.
Although he missed out on the world record of 22.73 metres, Gill did set new championship records, first in the morning's qualifying round with a 21.50m distance and then improving on it three times during the final.
All six throws in the final were in excess of the previous championship record.
Gill declined the opportunity to compete at the London Olympics this year, preferring to concentrate on retaining his junior title, but has his sights set firmly on qualifying for the senior world championships in Russia next year.
