After defender Dan Harding broke the deadlock, Lambert notched his 16th of the campaign from the penalty spot after Marlon Broomes was adjudged to have handled.
Lambert topped off a solid display with a stunning free-kick, curling the ball in from 30 yards after Craig Curran had fouled Harding.
It prompted Pardew to say: "I don't think I've ever seen anyone hit a ball harder than Rickie.
"He's been threatening to do that all season and he got it right in this game. He does practice in training but he's just a natural clean and hard striker of a football."