Wenger acknowledges the importance of the maiden strike in Arsenal colours, with the £46.5m signing from Lyon - a club-record fee for the North Londoners - taking little time to make an impact for his new side.
Speaking to reporters after the match, Wenger said: "It is important for him to get that [first goal] off his shoulders. You expect to score if you are a striker.
"You could see that he was happy but overall what we were looking for was to play at pace and to develop our collective game."
Lacazette scored 39 goals in all competitions for Lyon last season, taking his tally to 129 in 275 appearances for the Ligue 1 club.