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 Petr Cech in the Chelsea goal over the course of the game.
The win moves Chelsea 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 [for the Club World Cup in which they lost to Corinthians of Brazil in the final].
He said Norwich had beaten Manchester United and Arsenal "so we knew it could be tough."
"I'm pleased for the team and pleased for Juan, " he said.
Benitez left Frank Lampard on the bench for the trip to Norfolk amid speculation he will leave Stamford Bridge next summer.
But the former Liverpool boss was bullish about the future of Lampard and his fellow England star Ashley Cole.
"From my position it is very easy, it is a private conversation between Frank and the club and that is it, Benitez said. "He is a good player and I would like to bring the best from him, that is my position.
"I don't know if Ashley has had the conversations or not but, for me, they are players under contract, good players. After being injured like he [Lampard] was, we needed fresh legs and we have to manage the squad. We can't play so many game with the same players so we have to manage and everyone is important."
Chris Hughton, the Norwich boss, was pleased with the endeavour shown by his side to limit Chelsea to only a few chances.
"I thought we dealt with them for really big periods of the game, the chances they had I thought were fairly minimal, we restricted them," he said.
"As the game opened up in the second half I think we broke very well and showed good energy and might have got a draw in the end."
But Hughton was unhappy with the wastefulness his players showed when they were in possession. Mata's goal came after Norwich had gifted the ball to Chelsea.
"The area I was disappointed in during the first half was that, we have been good on the ball, but we were a little bit loose and it allowed them to have three or four good counter-attacks," said Hughton.
"We dealt with them eventually very well but it was a ball that was given away [that led to the goal], they broke very well and we got bodies around the ball but I think you have to admire the strike."
Everton 2 Wigan Athletic 1
David Moyes lauded his side for keeping up the Christmas cheer up as Everton beat Wigan Athletic 2-1 at Goodison Park. “I’m happy with how well the players have done over Christmas. They’ve been really good and had to be again today,” the manager said after Leon Osman and Phil Jagielka ensured their Champions League challenge was back on track.
Osman broke the deadlock with a deflected opener early in the second half before Phil Neville marked his 500th league appearance by setting up Jagielka for the second. Arouna Kone gave Wigan a late lifeline but it was not enough.
Aston Villa 0 Tottenham Hotspur 4
Tottenham Defoe 57’, Bale 61’, 73’, 84’
A Gareth Bale hat-trick piled more misery on Villa last night as Tottenham handed them a second heavy defeat in four days. Coming on the back of a 8-0 thumping at Chelsea, Paul Lambert would have been expecting a response from his charges. But after Jermain Defoe opened the scoring in the second half, Bale, right, ran rampant, notching his first Premier League treble in the process.
Reading 0 Swansea City 0
Reading ended a run of seven consecutive defeats with a scoreless draw with Swansea City. The Royals are still rooted deep in the relegation zone but they were the only one of the bottom three teams to get any kind of a result yesterday, while Southampton also drew. After conceding nine goals in their last two home games, Reading’s onus was clearly on keeping a clean sheet and their goalkeeper Adam Federici secured that by saving well from Nathan Dyer and Ki Sung-yeung.
Fulham 1 Southampton 1
Fulham Berbatov 08’
Southampton Lambert 85’ (pen)
Rickie Lambert’s late penalty secured Southampton a hard-earned point at Fulham yesterday. Fulham came into the match with just one win in 10 matches but got off to the best possible start, taking the lead inside eight minutes through Dimitar Berbatov, but Chris Baird handled a Gaston Ramirez corner, allowing Lambert to continue his 100 per cent success rate from the spot five minutes from time.
QPR 1 West Brom 2
QPR D Cisse 68’
West Brom Brunt 29,
Green 49’ (og)
Robert Green had a day to forget as QPR sunk to the bottom of the table with a home defeat to West Brom. Chris Brunt beat the England stopper from 30 yards in the first half with a shot he perhaps should have saved. Green then dropped the ball in to his own net to give the Baggies a 2-0 lead just after the re-start. Rangers pulled one back through Djibril Cisse.