Gabriel Agbonlahor struck the only goal of the game as Lambert's side pulled off the shock of the weekend thus far.
"Tactically it was fantastic," he told reporters.
"You've got to have lads who will go and try to carry it out and right from the off they were outstanding. We started with two up front and then we changed it - it worked.
"In the first half we had two or three chances. Philippe [Senderos] should have scored with his header and Andi Weimann's shot. It was a fantastic performance and a fantastic result."
Victory over the Reds saw Villa enjoy their best start to a Premier League campaign in 16 years, after picking up three wins and a draw from their opening four games.