The visitors spent much of the opening exchanges on Saturday inside their own half, with their penalty area under attack almost right from the kick-off.
But despite the early dominance, the Reds didn't really trouble Jets' goalkeeper Noah James before the visitors took a surprise lead on 36 minutes through Lachlan Rose.
The opening goal settled Newcastle but Adelaide did manage an equaliser in first-half injury time through Stefan Mauk.
Stanton's side were a much tougher prospect in the after the break and Clayton Taylor found the winner on 55 minutes.
"I think we're more than capable of defending our box and our zone; we do a lot of work on it," said the coach.
"Some people are critical of that, but I think we handled it pretty well. I didn't really feel like we were going to concede.
"I didn't see a lot of accuracy, a lot of commitment, a lot of committed shots from Adelaide. I knew we were committed.
"In saying that, a team like that, if you let that happen for too long you are going to concede which we did, so that was disappointing at half-time."
Mid-season signing Kota Mizunuma produced a man-of-the-match performance in his first start for the Jets since arriving three weeks ago.
The 34-year-old delivered a pin-point delivery for Rose's goal, notching his third assist in four matches.
Stanton is delighted the Japanese winger has penned an 18-month deal and has already seen his impact.
"He's an exceptional player. I sold him the project of what we're doing and it was at the right time for him to do this," he said.
"Once we had a good discussion about what we're trying do, he was really keen to come and obviously I'm really happy to have him.
"He is just a good human being, brings a presence and a cultural thing to the change room that we're getting benefit from."
United coach Carl Veart, though, was disappointed with the Reds' performance at both ends of the ground.
"We still created enough opportunities in that first half to score goals, we just didn't have the finesse or the quality to finish those opportunities off," he said.
"And defensively tonight we were quite poor all over the pitch. Our effort to defend and press the ball was not at the level that it needs to be."
