Four players aged 19 or under were named in the Spurs line-up in Budapest with full debuts handed to academy graduates Mikey Moore and Will Lankshear, who starred amid the white-hot atmosphere at Groupama Arena in Budapest.
Postecoglou's side, which had an average age of 23 after teenage pair Archie Gray and Lucas Bergvall also started, held off a barnstorming finish by the home side to edge the victory.
Gray gets a hug from Spurs scorer Brennan Johnson. (AP PHOTO)
Asked if his youngsters could be called Ange's Angels in reference to Manchester United's Busby Babes and Fergie's Fledglings, Postecoglou laughed: "Nah, nah, nah, nah -- you've got to do better than that. No, no chance!
"The first thing is that they're part of our first-team squad, not because I want some young players, it's because they've earned that spot.
"Then it's about how to help them develop and the moments we need to put them in there, the moments we need to hold off. And we can't discount the fact that Archie is 18, Lucas is 18.
"I thought Archie was brilliant. We asked him to play in two different positions and it's incredible how he just adjusts and he's able to bring his game to wherever he put him.
"Lucas worked hard and Will was unlucky with a couple of moments when we could have got a goal.
"These guys are there because they've earned their spot but they're an important part of our development."
Moore has been a name on the lips of Tottenham fans for more than 12 months and in May become the club's youngest player to appear in the Premier League when introduced late on against Manchester City.
The recently-turned 17-year-old has kicked on since with a strong pre-season followed by this first start, where his driving run helped create Pape Sarr's opening goal.
The Spurs academy graduate also produced a number of other decisive passes, including to set up Timo Werner for a golden second-half chance.
"I thought Mikey was outstanding. It's brilliant for a 17-year-old to play 90-plus minutes in a European away tie," Postecoglou reflected.
"He just handled it superbly, I kind of knew he would and I think it'll help his growth as a footballer once you get through an experience like that.
"I think he'll grow and evolve and I didn't feel like I needed to take him off. He still looked strong at the end and was still contributing."