Returning home to celebrate their first-ever title win with 20,635 fans, it was Bayliss, one of Auckland's new signings, who introduced himself in style on Saturday afternoon.
Tapped to start by Pedro Moreira, who replaced Steve Corica as coach after the latter's move to J1 League side Yokohama F Marinos, Bayliss first struck with a highlight-reel blast in the 35th minute.
Telling Sky Sport post game that he was told to "Make a name for yourself," by Moreira, he then netted again in the 53rd, restoring the hosts' lead after Quinn Macnicol's equaliser.
Lachlan Brook removed all doubt with an 85th-minute dagger, keeping Auckland unbeaten in round one across their three-year history.
"I relish the challenge to have to perform and contribute," Bayliss added.
"I'm glad I was able to show that on the first day."
The result continued a horror run in Auckland for City, who have now lost their four trips to Mt Smart Stadium by a combined score of 10-2.
They'll lick their wounds ahead of a Melbourne derby against the Victory next week, while Auckland will travel to face the Wanderers in western Sydney.
"We knew that if we made errors, they were going to punish us," City attacker Andrew Nabbout said.
"They're a good side; they're champions for a reason."
A back-and-forth contest begging for a moment of inspiration, Bayliss pounced on an errant pass from Besian Kutleshi and drove a first-time bomb from 35 yards out to bring it to life half an hour in.
The better side to then, it gave City the impetus to produce a moment of class themselves, as a 42nd-minute square ball from Kavian Rahmani teed up MacNicol to fire into the bottom corner for 1-1.
The contest was largely defined by muscle before the goals, with a late challenge from Jake Brimmer on MacNicol sparking an all-in shoving contest that saw Sam Cosgrove and Aziz Behich booked.
But a quick transition soon after halftime put Auckland back ahead, as City's headed clearance of a Hiroki Sakai cross sat up perfectly for Bayliss.
Brook then cut inside and curled in a shot from atop the box to ensure the result late on.
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