The young Magpies got off to a flying start through Victor Fernández's drilled finish before Tom Allan's penalty extended United's advantage.
Jessic Ngankam halved the deficit for Hertha in the latter stages of the Group C clash but Allan's second penalty of the night secured maximum points at Whitley Park.
Allan told nufc.co.uk: "I thought it was a really good start to the game, getting our noses in front early on. We played some excellent football in the first half, got the ball down and caused them a lot of problems, particularly the front four with their pace and little combinations.
"We mentioned about these European games in particular where they don't know what to expect in terms of turning up here and the cold night so it was important to start brightly.
"Victor's position was difficult for them to pick up and we managed to get him in the ball a lot and a lot of our good play went through him. Liam (Bramley) made the point at half time that no two halves are the same so as well as we had done in the first half, we knew that, given the scoreline, that they would have to come and have a go.
"It was important for us to try and keep a clean sheet which would have been nice but we managed to get the third goal to get the goal difference back up to plus two hoping that if we can get a positive result and performance against Blackburn, it might give us a chance to top the group and go through.
Newcastle's second-string sit in second place of Group C but, with leaders Benfica on seven points after playing all three matches, a win against Blackburn Rovers next Friday would send Dawson's side into the quarter-final stages.
United did not participate in last season's tournament but reached the semi-finals in 2017 and, after reaching the Premier League Cup final last term, believes the cup competitions can benefit the developing youngsters.
Dawson added: "A lot of the lads were involved in the cup runs last year so it's good experience for them. They are becoming more vocal and demanding of each other.
"They know what the expectations are and it's important that the lads who are new into the group this year need to learn from that and quickly because the games come thick and fast.
"For us, it's a really good competition. The two teams who we have played from abroad so far have been good games and different to what we get in the league and cups here. It's always nice, in terms of the performance and result, to build confidence and hopefully we can take forward to Monday away at West Ham.
"I think we are quite an attacking and exciting team at times. We move the ball quickly and do the things that we practice. The key, as always, is we have to do better without the ball to make sure that if we are scoring two or three that it is seeing the game out for us and we aren't needing to score four or five to win.
"There's still plenty of work to be done as there is on the in-possession and transitions either way but they are a good group to work with. They work hard everyday and are trying their best to listen to the information and practice the things we want. It's pleasing when you see some of that transferred onto the pitch in the game."
