The Canaries defended resiliently throughout the game and threatened at the other end, with Holt and Morison testing Chelsea's rearguard.
The 30-year-old striker revealed that his side had altered their game plan to get a result and was delighted with the effort of the players.
"It was a massive result," Holt told Sky Sports News.
"We talked all week about getting our shape and staying tight and I thought we were fantastic.
"We wanted to force them wide and we did. If we keep working and playing in that manner we will be okay."
The draw leaves Norwich ninth in the Premier League table.