Strikes from Paul Gallagher and Andy King gave the Foxes a two-goal lead before Jacob Mellis halved the deficit. Further strikes in the second half from King and Kyle Naughton kept City unbeaten in 2011.
"We didn't play our best football in the first half but in the second half we got better and the four goals means I am very happy," said Eriksson. "All the goals were beautiful and the last one by Kyle Naughton, he has a good shot, but that was incredible."
Eriksson played down City's promotion prospects despite Barnsley manager Mark Robins describing City as the "best side in the division".
Eriksson said: "I hope he is right, it is very far away but we are on a good run and 2011 has been very, very good to us.
"I'm not thinking about the play-offs. We are better thinking about our next game at Derby next Saturday."