The 24-year old Czech striker joined Villa from Lazio in the summer and opened his account not long after coming on to replace Christian Benteke in the first half at Carrow Road.
"I am happy," said Kozak. "I scored in my second game at Aston Villa, we won the game so that is the most important.
"First touch I can score it, but the goalkeeper saved.
"After Gabby's great assist it was easy for me to score. We played together as a team, all of the players helped me when I entered the pitch.
"It was great that we won the game because it's not easy. It is very positive and Brad was a magic man, he saved the game."