The France international, who was signed from Wigan Athletic for £9.5m in July 2011, won the penalty which Belgium international Christian Benteke duly dispatched in the 74th minute.
The 26-year-old returned from injury in January, and the former Newcastle winger scored his first goal of the season with a super set-piece, before Ashley Westwood scored a late own goal.
“The free-kick was world class,” said Lambert.
“He has that in his make up. He’s a really talented footballer. Those type of players aren’t easy to come by.
“Since he has come back from injury around the start of January, he has been excellent.”
Lambert also hailed a massive three points for the Birmingham outfit, which sees Villa move clear of the bottom three and into 17th place.
“We deserve a lot of credit for what we have done today,” added Lambert.
“I think it will be huge for us. We’ve taken a lot of knocks but football is a funny game and we are only three points behind Newcastle now.
“We know what we have got to do and there’s 12 games to go and every game is really tough. But that was a huge win for us, especially with the results for the teams around us yesterday.”