Lambert, who watched the game from the stands because of a one-match ban, was full of praise for his side's performance - which moved them out of the bottom three.
He said: "We've played the two Manchester clubs and Arsenal in back-to-back games and it's a tough thing mentally.
"But I thought we played really well today. We were excellent and might have nicked it.
"We defended really strongly. We are playing really well.
"We are a young side which is growing together and the way we are playing, we are a threat."