My father usually drinks beer, but tonight he had wine.

Literal

Father [topic-は] usually beer [object-を] drink [but-が], tonight [topic-は] wine [object-を] drank.

Contrasts a habitual action (普通ビールを飲む) with an exception (今夜はワインを飲んだ). The contrastive は on 今夜 emphasizes the departure from routine.