The 44-year-old confessed his delight at his side's fightback having gone two behind and praised their maturity, yet Pepe Mel rued referee decisions he felt went against his side
Lambert watched as the visitors took an early lead to put themselves two ahead inside the first 10 minutes, but a thrilling fight-back and second-half Christian Benteke penalty earned Villa the bragging rights.
The Scot afterwards admitted he was delighted with the turnaround and believes his young side showed character in the manner in which they secured all three points.
"Two-nil down in any game after eight minutes is tough, but in a derby game it doubles because of the importance to the crowd," he admitted in his press-conference. "But the turnaround was fantastic.
"To turn it around, the way we did it, was absolutely fantastic. You never lose faith in them as there was only eight minutes gone and we kept a level head. We showed a lot of maturity in doing that.
"It was really unpredictable the way the game was going. You’ve got to hold your nerve and I thought we did that.
"To lose the goal just before half time was really disappointing but the turnaround was unbelievable."
Baggies boss Pepe Mel was disappointed at leaving with no points despite having scored three goals away from home, believing Benteke was the difference between the two sides.
"The first 15 minutes at the start of the game is good for us but it is incredible to score three goals away from home and receive no points," he admitted.
"I believe our problem in this game was Benteke not so much our defence. We’ve worked all week on the direct play of Aston Villa but I think this was our problem.
"It was a good spectacle for those who paid their entry money. Both teams were trying to win and we produced a good spectacle. [But] in the end we have no points."