Lambert saw his side, with an average age of less than 24, take another step forward by holding in-form Stoke to a goalless draw at Villa Park and extend their own unbeaten run to four matches.
Fears that Villa's group of 'tiny tots' would be outmuscled by the Potters proved unfounded, and they coped admirably with the physical threat of Kenwyne Jones and then Peter Crouch.
Reverting to a back-three of Ciaran Clark, Chris Herd and Nathan Baker for a second successive week proved effective and Stoke created only one chance in the entire 90 minutes.
Lambert said: "When they go out there to play, I trust them. Some of the football we're playing has been very good.
"But I was also delighted with the way we coped with Stoke's strength. It is hard to keep Stoke at bay with the way they play.
"I was asked before the game how we would combat that and I think we used our strengths by playing football. I thought we were excellent.
"When I came here, I knew be it would be a long-term thing and that's what we're trying to do.
"We are trying to fix it really quickly and sometimes you need that time together.
"But I am not just putting them out there to learn. I know they can handle it and the last few weeks we've been very good."
More experienced defences than that at Villa have been unable to contain Stoke's threat in the air and from set-pieces.
But Lambert said: "You look at the three of them, all young lads, and I thought they coped really well against a physical front-line that Stoke have got.
"Playing three at the back is something we think will benefit us and the players have adapted brilliantly to it and are playing with a lot of confidence at the moment."
While Villa have tightened up at the back, Lambert knows his side also have to improve on a record of 12 goals in 16 league games - the worst in the division.
He reintroduced Darren Bent as a substitute, his first action for nearly six weeks, but is more concerned at finding the right blend than focusing on the club's record signing.
Lambert said: "Darren did fine. It is hard as a sub to come on and adjust to the game but he did really fine.
"Can he play alongside Christian Benteke? Listen, the most important thing is the team - and the team I pick I hope is the one that will win us the game."
Stoke boss Tony Pulis chose his words carefully but was unhappy with decisions made by referee Roger East, including the injury-time sending-off of defender Ryan Shotton for two yellow card offences.
Replays appeared to show Shotton made no contact with Villa substitute Fabian Delph in the incident which led to his second booking.
But Pulis was also mystified after a first-half lunge by Villa defender Ciaran Clark on Stoke midfielder Glenn Whelan went unpunished.
He said: "People will judge what they think in terms of Ryan's two challenges and the challenge on Glenn at the end. Goodness knows what the ref has seen and hasn't seen.
"But you've got to be very careful what you say. You can't criticise them. You can't say they are doing anything different for either side.
"I'm not going to stand here and say that because they will take some more money off me."
Pulis was happy with a share of the spoils which followed on from the win at West Brom last weekend.
He said: "It was our second away local derby in a row and we've come away with two clean sheets and four points, so it's a great tribute to the players.
"Villa are a young team playing with loads of confidence, everyone is having a go for the manager, and we are pleased with a point."