The Hammers made Villa look second rate for the first 55 minutes, with the first of Kevin Nolan's two goals coming just 15 seconds into the second half with a cheeky inside flick to a low Stewart Downing cross.
The second followed two minutes and 43 seconds later as he robbed a dithering Fabian Delph just outside the area before taking the ball on into the box and stroking it crisply past Brad Guzan.
At the final whistle a chorus of boos and jeers greeted Villa's latest miserable home performance and Lambert said: "The two goals were really disappointing, especially right after half-time.
"I don't think I'd taken my seat when they played a long ball and we never dealt with it. Whether you're young, old, or an experienced player, you deal with it. It was just a long ball and we should have dealt with it better.
"The second goal was just a basic error and then all of a sudden we came into life in the game. But conceding two goals is just not good enough.
"The two goals irritated me because at half-time we've gone in level and in the second half we're attacking into our favourite end and you think something's going to happen.
"But the two goals during that two-to-three-minute spell put us on the back foot. They were unacceptable and you cannot defend that way at this level."
- Sports & Recreation
- Christian Benteke
- Kevin Nolan