The victory was the first in nine games for Lambert's side and the former Norwich City boss hopes that his team can build on it.
"It's a huge win for us," said Lambert. "We have been in positions of being goals up in a few games.
"If we had taken more points from those, we'd be comfortably in mid-table. But the pleasing thing is we have hopefully broken the camel's back with that.
"It's only great when you hear that whistle and you've won. It's the only good thing about it. The stress levels are ridiculous."
Villa now face Arsenal in the Premier League.