Last season's fixture was a nightmare for the Argentinian, who was red-carded in a 3-0 defeat.
He admitted: "It's a much better feeling this year!
"I had to forget about what happened last season. I was sure going into this game I wouldn't have the same problem. I was determined not to suffer that again. The team played very well and we kept the same level we showed against Real Madrid.
"We have to keep going the same way. It was a great day for the supporters and we are really happy. To beat Real and now United with four goals in each game is very good."
He added: "When you have key players like Fernando and Stevie Gerrard in front of you, and in that form, it gives you confidence that you can always go on and win.
"All we can do now is keep going. There are still nine games to go and we need to win every single one to have a chance of catching United."