Grant Holt opened the scoring in the first half and the Canaries were heading for another three points until Adam Drury sent the ball into his own goal to give Doncaster a point.
"We have set ourselves very high standards this season and I can sense a feeling of disappointment at the end, but you've got to remember how far we have come in a short space of time. It's incredible," said Lambert.
"The last time this club was in the Championship they couldn't buy a win. I am not going to get too down about drawing a game when we are fifth in the league with everything to play for.
"There's still a lot of football to be played and a lot of sides will drop points when no-one expects them to. Look at some of the other results."
Source: PA
Source: PA