Marshall superbly palmed away a deflected strike from Fabian Delph late on in the game, but he managed to better himself in the final minute of stoppage time, pulling off one of the saves of the season to acrobatically tip an Andreas Weimann effort over the bar.
Despite Villa's late onslaught, Cardiff did have the better of the chances in the opening 45 minutes, twice hitting the woodwork as they looked to pull themselves out of the relegation zone.
Villa dominated the second half but were ultimately unable to find a way past the hosts and Lambert's former Celtic team-mate Marshall.
Asked if he was frustrated with the result, Lambert told Villa's official website: "Yes, very much so. In the second half I thought we were fantastic and there was only one team looking likely to win it.
"Marshy, who I knew at Celtic, kept them in it. He made two world-class saves, especially the one at the end from Andi.
"I thought Leandro (Bacuna) and Gabby (Agbonlahor) should both have scored, and I felt Christian (Benteke) should have hit it instead of trying to pass it."
However, Lambert did praise Cardiff as Ole Gunnar Solskjaer watched his side put in a spirited defensive display to keep their first Premier League clean sheet since December.
"Cardiff have beaten some really good teams here," he said. "Ole has a good side and this is a hard place to come.
"But I felt we should have won. Even when Cardiff hit the bar and hit the post I wasn't too concerned."
Lambert also hailed captain Ron Vlaar who returned to the starting line-up having missed the 2-0 defeat to West Ham with injury.
"Ron was very good," he said. "It was touch and go whether he played on Saturday.
"He gives us that balance and I thought he played really well. This could be a huge point for us."