It was a dominant performance from the Nerazzurri in their rescheduled Week 12 match with goals from Zlatan Ibrahimovic - from the spot - David Suazo and Douglas Maicon.
Mancini said: "Lazio started brightly and covered all the spaces, while we had a bit of a sluggish opening. After 10 minutes we started to play, opened the scoring and from then on Inter did very well."
"For now the only difference between us is our 4-1 victory at the Olimpico. Roma are doing very well and the table is already giving its verdict - Inter and Roma are the best, but in the long run Juventus could recover."