Kingsley Coman, Robert Lewandowski and Thomas Muller goals earned Bayern a 3-0 victory over the Serbians in the German giants' Group B opener.
"He played a really good game and with his football intelligence he brings another dimension to our game," Kovac told Sky in Germany.
"I think we can be very happy. The team has been very focused and we scored three goals, that's befitting."
Muller came off the bench to make a club record 106th appearance in the Champions League for Bayern, but he played down its significance.
Muller said: "Such game records are something for after the career, and I'm not going to give up my shoes up in the near future, so it's not that important."
Red Star captain Marko Marin came agonisingly close to an equaliser before Lewandowski and Muller's strikes late on, and the 30-year-old attacker insisted the result was not a fair reflection of the game.
"We saw that Bayern are on another level," Marin said. We could have scored from our chances. They deserved a win but not the last two goals, they hurt the most.
"Let's not forget that this is our first group match and playing away, so I hope that we will make up against Olympiacos."
Olympiacos held Tottenham to a 2-2 draw in the group's other game and head coach Vladan Milojevic added: "As I said before the match, Bayern and Tottenham are the favourites in the group, and we saw why tonight. We are aware that we played against a possible winner of the Champions League."
Bayern return to action Saturday to take on Koln in the Bundesliga, with the club looking to claw their way back to the top of the table.
They currently sit two points back of leaders RB Leipzig through four matches.