Eighth seed Evans broke serve five times in the Australian Open warm-up event and needed just 77 minutes to defeat Auger-Aliassime, who has now lost all seven finals he has played in.
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Evans capitalised on an error-strewn display from the Canadian third seed to break twice in the opening set and take control.
He did not let up in the second, the only blip coming when he was broken while serving for the match at 5-2. However, Evans produced an instant response to break back and seal victory.
"I said to (former coach) Mark Hilton just before my ban that I wanted to make a final," Evans told reporters when asked about the significance of lifting his first trophy. The goal that year was to win a title.
"Of course I wanted to win one, but today was just another match. I approached it in that way. Everybody wants to win, it's a great feeling."
The triumph comes four years after Evans was hit with a one-year ban for cocaine use. He had broken into the top 50 for the first time in 2017 and reached the last 16 at the Australian Open, his best performance at a Grand Slam.
Evans said his form leading up to the event had been patchy but that the title would give him a major boost heading into the first Grand Slam of the year. He faces compatriot Cameron Norrie in the first round on Tuesday.