It was a second consecutive away win for Norwich, who remain ninth in the table.
Lambert said: "It was an absolutely fantastic result.
"I thought the lads were excellent. They defended really strongly when they had to and counter-attacked really quickly, which was great.
"With the first goal Wes Hoolahan plays in the cross and it still has to be finished, which Surman does perfectly well.
"For the second, Holt does fantastically for us and then what a header from Morison, because he has to get above a defender and beat the goalkeeper.
"I am absolutely delighted. The lads put their bodies on the line and Ruddy was on top of his game - great credit to the lads for the way they defended."