Millwall Under 23s manager Kevin Nugent has credited the display of his young Lions after being narrowly beaten at Calmont Road against Crystal Palace.
Lewis White's early opener gave Nugent's side a half-time lead, before Harry Donovan's red card shortly after the break forced Millwall into a committed defensive mindset.
Brandon Pierrick and Levi Lumeka later struck to give the visitors all three points in the Professional Development League clash.
"I thought it was a very tight game, and a real, competitive local derby," Nugent says.
"We had an excellent start with Lewis White's early goal. I'll have to have another look at the sending-off - which did change the game - but I was really proud of the lads today because they gave it everything.
"When you get a red card early in the second half, it is going to be difficult sometimes to hang on. But I'm pleased for the performance of the team and disappointed for them not to have taken something from the game."
Competing with the numerical disadvantage was an interesting factor for Nugent, who claims it was a "learning curve" for his young players.
"I don't think either side had too many chances. We looked organised and showed flashes of some real quality play, and also some bright individual performances.
"At 1-0 I thought we had a deserved lead, but the second half was still a learning curve for the boys to try and stay compact and hold on, which unfortunately we weren't able to do this time.
"Palace are a good side with some very talented players, and they rotate well. On another day in a game like that, you do hang on."
With defenders Alex Pearce and Sid Nelson starting the contest, along with Dave Martin and Jiri Skalak, Nugent highlights the importance of the guidance for his youngsters from the first-team players.
"The voice of the two centre-halves was crucial - I said to the younger lads at half-time that it's important to learn from playing alongside these players with the skill and knowledge they have.
"Having Pearcey, Sid, Jiri and Dave was a real bonus for us today."
Nugent finally states he is content with the progress of his U23s, some of whom have recently been earning valuable senior experience on youth loans this season.
"It would be lovely to reach the top two [in the Development League]. Obviously, we're looking at individual performances and some lads are out on loan as well, so the team does change on a regular basis, but things are looking well for us."