The Red Devils eased to a vital win in the Premier League’s top-four race following goals from Romelu Lukaku and Jesse Lingard.
Lukaku cancelled out Willian’s opener in the first half at Old Trafford before Lingard netted a second-half winner at Old Trafford.
Manchester United extended their lead over Chelsea FC to six points to cement their place in the Premier League’s top four.
Mata was an unused substitute against his former club but the Spanish forward still savoured an important win for the Red Devils.
The 29-year-old spent two and a half seasons at Chelsea FC before the Spanish playmaker was sold to Manchester United in a £37m deal.
Mata explained why Manchester United’s games against his former club remain so special for the World Cup winner.
“It’s just a few hours since I came home from Old Trafford after playing Chelsea, a game that is special and will always be special for me,” Mata wrote on his personal blog.
“It was an even game, very intense too, and we managed to win and to get three points that are very important for us. A victory at home is always more satisfying because as soon as you leave the dressing room you see everybody around, your fans…, and they all have happy faces.
“It’s a great feeling, even more after a comeback against such a good team. We were able to recover despite Willian’s goal to get the three points that keep us in the second place of the table.”
Mata has won the Europa League, the FA Cup and the League Cup since his move to Manchester United in a big-money deal from Chelsea FC in the 2013 January transfer window.
The Spain international has scored three goals and has made four assists in 22 appearances in the Premier League this term.
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