Despite not hitting the heights of the 8-0 thrashing dished out to Aston Villa on Sunday, Chelsea were the better side in a game that lacked any sustained quality.
Mata struck from 25 yards in the 38th minute to settle the match and condemn Norwich to a second defeat in four days, with the Canaries failing to truly test Chelsea goalkeeper Petr Cech over the course of the game.
The win moves the Blues to within four points of Manchester City in the Premier League table and Benitez was full of praise for his compatriot.
"He is playing really well," he said.
"Even without the ball he is working hard but when we are in possession he is making the difference, I always say the same; if the team are playing well these players can make the difference.
"I think the Premier League has a lot of good players and Mata is one of the best for sure - he can be even better.
"Mata is a player who is dangerous - inside the box and outside the box, we are really pleased with him.
"The team has won three games in a row since Japan...against Man United and Arsenal they (Norwich) have won so we knew it could be tough, I'm pleased for the team and pleased for Juan."