The Kings came down from 14 to level the scores, but Newbill's bucket - part of a 22-point display - was supplemented by Kirk Penney and Shea Ili to get the Breakers over the line.
Penney hit six threes in a 25-point outing, while Ili's all-around production helped the Breakers overcame a sluggish first quarter to - eventually - clinch the win.
While the Breakers don't profile as the most electrifying offensive team, they found themselves ensconced in a high-octane start as both sides found early success from beyond the three-point arc.
The Kings were causing the Breakers issues defensively with their smaller, stretchier lineup, as their big men rained in early threes. The Breakers struggled to guard them, but kept in touch through a balanced, if a little isolation-heavy, offence.
A balanced offence is likely what the Breakers will require this year to be successful. Paul Henare's side doesn't have a player who can be consistently counted on for offensive outbursts, instead relying on a roster which goes at least nine deep with solid contributors.
After Tom Abercrombie and Edgar Sosa were the main offensive options in their opener against the Cairns Taipans, this time it was a new trio to boost the Breakers.
After a week where he was felled by illness, Penney's quick, consistent release from three-point land was the initial spark for the hosts. Coming off curls and screens, Penney was launching at any opportunity, and was fouled twice on three pointers to enjoy some easy points at the free-throw line.
"I felt pretty light tonight - everything had been squeezed out of me all week," he laughed.
That gave the Breakers their first lead of the game, and Ili came off the bench to extend it. The NZ NBL standout showed his evolving talent by getting to the rim, taking charges and dropping dimes - stretching the Breakers' advantage to 13 by halftime.
Henare was pleased that his side has multiple players who could step up to shoulder the offensive load.
"We can be multi-dimensional in terms of teams scouting us, I do think we have guys on any different night who can put points on the board. It gives confidence to anyone who steps on the floor."
The Kings slowly chipped away at the Breakers' lead, but Penney's continuing production and Newbill's impressive isolation scoring kept the Breakers in front. That was, however, until the final seconds, when a Perry Ellis tip-in created the possibility of a stunning comeback.
However, Newbill ghosted past his defender, went to the rim, and made sure he'd make a memorable early mark in his Breakers career.
Henare talked up the composure of his squad to grind out the win.
"Sydney are a good team - they did a good job at putting pressure on us towards the end, but I was proud of the guys for hanging tough. To have that composure at the end, I'm really proud of the guys."
The Breakers can quickly build on their success, with their next clash on Thursday, at the same venue, against the same team.
They will be hoping for the same result.
New Zealand Breakers 87 (Penney 25, Newbill 22, Ili 15)
Sydney Kings 85 (Ellis 19, Lisch 17, Leslie 15)
HT: 54-41
