Christian Benteke is developing a thriving partnership with Weimann who has started to realise his potential since being an extended run of games under Lambert.
The understanding was demonstrated via Weimann's sublime finish after Benteke's back heel for the second goal at Anfield.
Lambert said: "Andi (Weimann) was here long before I came in. He's a natural finisher and has an incredible work-rate for the game of football.
"He's a totally different player to Christian, but he certainly knows where the goal is.
"We try to let them have the freedom to go and play and create.
"The second goal against Liverpool had great build-up and the finishing touch was the backheel from Benteke while the hardest part of the game is putting the ball in the net."