The midfielder took his tally to 20 goals this season as the Blues ran out 5-0 winners.
"That is the only time I have scored a hat-trick in my career. I am very happy and I think it is very important for the confidence for the next game," BBC Sport quotes him as saying.
"The team played very well. Credit to the manager because we are playing more attacking, we are always pressing high.
"It's very easy for me to be concentrating on doing something like I did today. We have only one thing to think about, the Premier League, Chelsea have two. It is going to be very, very tough and tight."
Man City are currently third in the Premier League table.