Has an NBA game ever ended 19-18?

Exactly once. On November 22, 1950, Ft. Wayne Zollner Pistons beat Minneapolis Lakers 19-18, and no NBA game before or since has ended that way. When it happened it was a scorigami, the first 19-18 in league history.

Where 19-18 sits among nearby NBA scores. Deeper blue means a score has happened more often; the outlined cell is the new one.

That makes 19-18 the 2546th most common final score out of 3,190 that have ever occurred in NBA. One point away, 20-18 has happened never and 19-19 has happened never.

Every 19-18 in NBA history

Date	Result	Season
1950-11-22	Ft. Wayne Zollner Pistons over Minneapolis Lakers	1950

Open the NBA grid at 19-18