Newberry, who had only been on the pitch for around 15 minutes, scored what proved to be the winner after he got his head to a Kirk Millar free-kick to nod the ball beyond Rohan Ferguson on 77 minutes.
The result keeps Larne top of the Danske Bank Irish Premiership standings, five points clear of second-placed Cliftonville, who have played a game less than their east Antrim counterparts.
Speaking to Larne’s media director Ian Cahoon after the tie in south Belfast, manager Tiernan Lynch said: “I think we are more disappointed with the manner in which we lost the game tonight. We probably saw it as a hame of two halves. In the first half we were very good, we were dominant, we moved the ball well, we got ourselves into good positions and we created a couple of really good chances.
"In the second half we struggled for the first 10/15 minutes to get out of our own half. Corners and free kicks- probably disappointed about the manner in which we gave away some of the free kicks, albeit I don’t think some of the free kicks were free kicks. I felt we needed to do more in the second half to get something out of it.”
Reflecting on the first half, Lynch explained: “I think when you are on top at places like Windsor you have to be clinical and you have to take your chances. It’s very hard to knock these players or fault these players- they are as honest as the day’s long and they give everything they have. They are hugely disappointed in there tonight.
"We never got a foothold in the game because we seemed to just defend so many set pieces. Linfield are a big strong side and they looked like they were playing for those set pieces. Their delivery was excellent and we got punished in the end.
"We’ll dust ourselves off. We’ll get over this, hopefully, very quickly and we’ll get ourselves organised for Coleraine (Friday, Inver Park, 7.45pm).”