Mata helped himself to another two goals in Tuesday night's 4-0 victory in Copenhagen to propel the European champions to the top of Group E after two matches.
The 24-year-old now has four goals and four assists in his four starts since returning from a fortnight off, directly contributing to almost two-thirds of Chelsea's goals in the past week and a half.
The Blues splashed out around £80million on new players this summer but Mata is outshining them all at the start of his second season at the club.
He said: "I want to improve. I feel I can still do better.
"Maybe this was one of the best weeks for me. I played well against Stoke, then Wolves, then Arsenal and now this.
"I'm feeling very well but I want to feel better and improve as well."
Mata is doubtless benefiting from the arrival of the likes of Eden Hazard and Oscar, as well as Chelsea's new attacking philosophy.
"It is a lot of fun to play in this shape, to play with players who like to play with the ball, quality players," he said.
"Last year, we won the Champions League and FA Cup, playing as we played.
"Now I think we can do it better, playing even better with Oscar, Hazard or whoever.
"All we can do is try to play our best but that is what we are doing."
Mata's form almost demands the number 10 role behind Fernando Torres but he was more than happy to play either side of that.
"At the moment I'm playing right side, which is good because it means I can cut inside on to my left foot," he said.
"When I play in the three behind the striker, I can look for freedom with the ball and help defending without the ball.
"It's important for all three of us to keep our positions."
Mata could also be forgiven for demanding the ball every time Chelsea earn a free-kick, but he made way for David Luiz towards the end of the night's game to spectacular effect.
He said: "If it's for a left-footed player, it will be me. If it's on the other side, maybe David or someone else.
"The important thing is that we have very good players. [Frank] Lampard can shoot as well, and me. We have a lot of players to take them.
"I'd wish that we could score from a free-kick in every game, whether me, Frank, Eden or Luiz."
Luiz said of the pecking order: "We have great players for shooting. We have Mata, Frank.
"They give me more confidence at the moment to take the ball and shoot.
"Before the game, we had the plan for the game. It was me, Lamps and Mata.
"On the pitch, it was who had more confidence."
Tuesday night's scoreline flattered Chelsea, who could have easily thrown away the lead before netting three times in the final 11 minutes.
Mata and Luiz both claimed the Blues' performance was the sign of a "mature" team.
Brazilian defender Luiz added: "I'm excited with the team and the other players, not only the Brazilians.
"Now is a great moment. Top of the league, the Premier League, and top of the group now in the Champions League."
The 25-year-old, who signed a new five-year contract a week and a half ago, added: "I'm so happy because they gave me more confidence.
"I love this club and I love to play for Chelsea.
"So five more years here is great. It's a dream for me."