From Longman Dictionary of Contemporary Englishfirst nightˌfirst ˈnight noun [countable] APthe evening when the first public performance of a show, play etc is given
Examples from the Corpus
first night• Moore spent his first night at the only hotel in the town.• I remember, that first night, sitting here thinking, how could we possibly do all that?• The difference in message and tone was established on the first night when retired Gen.• On the first night, more than half signed up.• Nutty did not take in much of what the Sergeant said the first night.• Oh I guess Tuesday night was the first night I had a hard time sleeping. 