The former São Paulo playmaker helped the Biancocelesti in their 2-1 win over arch-rivals Roma on Sunday, scoring his sides first from the penalty spot.
Hernanes believes Lazio are now a much improved side from a year ago and says the club are now in the race for the league title.
"This victory has great importance not just because it was a derby, but also because of the three points that keep us in the fight [for the title]," the 26-year-old told Globoesporte.
"Last year we failed to win in some important games, but this year it"s different. This is good because it shows that we have evolved."
Lazio currently sit in third position in the Serie A table, six points behind leaders AC Milan.
