In torrential weather conditions at the Exercise Stadium, the young Magpies fell behind in the opening stages of their final Northern Group F clash through Ellis Taylor's strike before equalising on the stroke of half-time, courtesy of Alfie Harrison's composed finish.
Tom Curson's second-half brace proved the difference for United's youngsters, with Lawrence admitting the beginning of both halves proved costly towards "a tough loss in the end".
"I think, when you look at the performance and break up the game in terms of bits, we took a while to get settled into the game during the first 10-15 minutes," he told newcastleunited.com.
"It's natural in some of these nights, it's wet and you're playing against senior opposition. I thought they settled into the game and found some rhythm, getting better as the half went on. We then started to use the ball well, getting a lot of territory and were looking really excited going forward.
"We were 1-1 at half-time and I thought we were good value for it. The biggest disappointment for us was the first part of the second-half. They started to press higher and trap us in terms of what we were trying to do and, maybe, in that period where we had to adapt and try something different, we kept playing in a similar way.
"There were two things within that period. One was our decision-making in terms of on the ball and when we needed to play into the front or break a line quicker and, secondly, how we handled the ball under pressure as there was moments where the structure was right for us to play and then the player didn't handle the ball in the way they should. Against senior opposition, they can punish you in those moments so the game ended up getting away from us."
Lawrence, who joined the Magpies' Academy in September following his departure from Manchester United, believes his side's involvement in this season's Vertu Trophy has been a positive one despite a heavy 6-2 defeat against Huddersfield Town within 48 hours of his appointment as the under-21s' Lead Coach.
After a penalty shoot-out victory against Mansfield Town in their second group fixture, following a 2-2 draw at the One Call Stadium, Lawrence thinks the contests against EFL sides have, ultimately, "challenged us in different ways".
The Bermondsey-born coach added: "Two of the three games have been competitive. The Huddersfield one was a tough one on the night in terms of the level of opposition on my second day in the job.
"If we have that game again tomorrow, we set the team up in a different way and maybe we're at a different point. In terms of the Mansfield game and then against Harrogate, we've been more than competitive in both games and been able to show some of the individuals and the quality of the team.
"It's good in footballing ways but in terms of the intensity of the game and the levels of duels, second balls and being able to compete highlights that in this competition.
"It's good for our lads to test and face. It gives us a different challenge to our normal games programme and exposing players to the level they are aspiring to play to so, in terms of a learning and developing experience, it's been positive on the whole."
