Has an NBA game ever ended 89-79?
Yes. NBA has seen a final score of 89-79 29 times. It first happened on February 10, 1950, when Boston Celtics beat St. Louis Bombers, and most recently on April 10, 2017, when Milwaukee Bucks beat Charlotte Hornets.
That makes 89-79 the 788th most common final score out of 3,189 that have ever occurred in NBA. One point away, 90-79 has happened 37 times and 89-80 has happened 38 times.