The 26-year-old says his goal against the Asian nation has given him hunger to prove his critics wrong.
The 26-year-old was on-hand to net the decisive goal in the 4-3 victory over the AFC nation in an enthralling clash which ultimately ensured the Azzurri's qualification for the Confederations Cup semifinals.
The Juventus attacker has dedicated the goal to his detractors who have previously cast doubts over whether he has the ability to succeed on the international stage.
"The goal against Japan was my first for the national team and it was very exciting," he told reporters. "It is the beginning of my international career and there are those who say I cannot play at the highest level, which I don't agree with, so my goal yesterday was a good way of getting revenge against them."
Cesare Prandelli's men finish Group A with a clash against host Brazil on Saturday to determine which team goes into the latter stages of the competition as group winners.