The result saw Jose Mourinho's side finish top of Group A, and Mata is looking ahead to Sunday's crunch Premier League clash with Manchester City on the back of a positive result.
"We needed to win, we only needed a point, but we always want to win," the Spaniard told reporters. "We are so happy, we face the weekend game with good momentum.
"It is important to win for your confidence level, Sunday is a big game (against City), we know how important it is, tomorrow we rest then on Thursday we will think about the game and hopefully we can get the three points."
United sit eight points behind City in the Premier League table going into the weekend derby at Old Trafford.