The 25-year-old, who smashed the world record when winning in Rio last year, finished over 46 seconds clear of her legendary compatriot.
The 25-year-old, who smashed the world record when winning in Rio last year, finished over 46 seconds clear of her legendary compatriot Tirunesh Dibaba, the three-time Olympic gold medallist and five-time world champion who took silver after being unable to go with the scorching pace of the winner.
Kenya's Agnes Tirop took the bronze.
"I am very happy to win this title, much more than when I won the Olympic gold because I have been sick this year and didn't expect it," said Ayana.
"In fact, this was my first race of 2017."
Dibaba was far from disappointed with her silver as she has been focussing on road racing.
"I have won many gold medals before but since I became a marathon runner, I only returned to the track for this race," she said.
"I knew that Almaz was going to run very fast, so if I had followed her, I wouldn't have won a medal."
"I know my capacity these days because my training for this race was very short," added the 32-year-old.
There was no indication early on that there would be such an outcome.
Unlike the men's race on Friday the pace was snail-like in the early laps -- Kenya's Alice Aprot not repeating her exploits of last year's Olympic final when her searing pace set up Ayana for the world record.
Ayana, who has been out of action with a succession of injuries, moved into second with 20 laps remaining as Uzbek runner Sitora Khamdova set the pace.
With 16 laps left, Khamdova beat the retreat and Ayana took up the pace with Kenyan-born Turkish athlete Yasemin Can in second and then three Kenyans with Dibaba trailing.
Ayana split the whole field as she sped clear with 14 laps to the tape, Can in no man's land between the leader and five other runners.
Ayana increased her lead at will opening up a gap of around 60 metres on Can with 12 laps to go -- Can was subsequently swallowed up by a group of four including Aprot and Dibaba.
By the eight laps to go mark she was stretching her lead even further to over 100m with the quintet behind seemingly now resigned to battling it out for the minor medals.
The only trouble she encountered was running into the back of an athlete she was lapping but even then she made light of it and nimbly side-stepped out of trouble.
Ayana simply carried on extending her lead to almost a lap and stormed home to thunderous applause and once Dibaba had finally finished went on a lap of honour with her.