Rafael Benitez's men have made a prolific start to the new campaign, scoring seven goals in two victories, with Hamsik grabbing four of them as Jose Callejon and Gonzalo Higuain scored the others.
Despite his goal-ridden start to 2013-14, the Slovakian - who has been given a target of 15 strikes by the new San Paolo coach - believes that strikers throughout Italy will soon leapfrog him in the table.
"I'm under no illusions. It is nice to be Serie A's leading scorer, but the strikers will now wake up," he told Corriere dello Sport.
"I'm delighted with how the term has begun - Benitez has asked me to score 15 goals and I feel I can do that."
The 26-year-old, who extended his contract with the club in August, was key in the Partenopei claiming second in Serie A in 2012-13 to secure Champions League group stage football this season.