Greene (16), a pupil at St Hilda's Collegiate, broke the women's aged 16 record of 4min 21.18sec that Sue Bruce (Canterbury) ran in 1981.
Greene's time of 4min 18.90sec was 3.08sec faster than the Otago senior women's record she ran in February.
Greene sneaked into the 1500m final by just 0.08sec at the championships in Moncton.
She will run the final today in a classy field that includes the top African runners.
Greene sat just behind the fast-starting African runners in Saturday's race and controlled her pace to be in fifth spot at the bell.
She maintained her focus and resolve down the back straight and finished strongly down the straight to snatch the last qualifying spot for the final.
University of Otago student Hannah Newbould ran 4min 19.71sec to narrowly miss qualifying for the final.
She missed her chance to be a dual finalist when she failed to maintain contact with the leading pack in the third lap.
Newbould finished eighth in the 3000m final last week.
