She managed to overhaul Crawford to stretch out to a lead a little over two minutes before facing another mishap when her shoes kept hitting the ground when pushing the bike through second transition forcing the classy American to pick up the bike to avoid losing time.
Kessler maintained her composure to run out the winner by 3:21.
"At the age of 36 I am at the pointy-end of my career and to gather as many of these titles as possible is really rewarding. Kiwi soil is good for me and I'm going to roll with it and hope it continues in Taupo [when Kessler bids for a fourth straight Ironman New Zealand title]."
Crawford had an unfortunate incident by the Harbour Bridge when her bike became trapped in a small ridge by the side of the road.
"I had to slow down and lost Meredith at that point - I didn't see her again," Crawford said.
"I was proud with how I performed I just didn't have that pace today to go faster than 1:26 [for the run]."
Her next big goal is also Ironman New Zealand.