Lori Loughlin in The Night Before (1988)

Winston Connelly wakes up in the middle of the night in an alley with no idea of how he got there. Nor does he know where in Los Angeles he is or why he is wearing a beat-up tuxedo. Through a series of flashbacks, he remembers that he was sidetracked on his way to the prom the night before. In the meantime, he has to figure out what happened to his wallet, his car keys, his date, and why a pimp named "Tito" wants him dead.