She was through the first 10km in 34m 39s and the halfway mark in 1h 13m 39s and passed Kiprop with less than two kilometres to go.
"As everyone else tired in the last four or five kms, Mary came through the field running the last two kms in a very quick seven minutes."
Betona Warga of Ethiopia won the men's race in 2h 10m 35s, followed by Kenyans' Kiplimo Kimutai and John Kiprotich in second and third.
Babe, who coached Davies to early success over shorter distances as a junior, began coaching her again two years ago via Skype and email.
"It has been great working with my coach Ian Babe again ... even though he is in New Zealand. He knows me and how my body works very well and has a lot of knowledge about running and training and life in general, which I have found very helpful," Davies blogged.
Babe said Davies has shown the power of perseverance after overcoming the disappointment of not qualifying for this year's Olympics with a hip injury. An inflamed sacroiliac joint forced her out of the Paris Marathon - her last chance to qualify after the birth of her son Lucas last year dictated a late build-up to the event.
But Babe said that's all behind her now and he is confident she will have more success in international marathons.
"She's really arrived on the world stage, anything under 2h 30m is a world class time and to do it against such a high class international field just shows what she is capable of," he said.
Davies was one of a group of outstanding Northland athletes trained by Babe. Her performance as a junior at the World Cross Country championships saw her recruited by Oklahoma State University into their athletics programme.
Soon after completing her studies, she married Gabriel, a Brazilian medical researcher, and moved to Houston before the pair relocated to Canada.
Davies' previous best marathon was 2h 38m 48s in Berlin in 2009.