Has an AFL game ever ended 89-76?
It has. 89-76 has been a AFL final 5 times in 16,622 games. The first was Footscray beat Fitzroy on June 28, 1975; the latest was GWS beat Geelong on April 3, 2016.
That makes 89-76 the 589th most common final score out of 6,607 that have ever occurred in AFL. One point away, 90-76 has happened 5 times and 89-77 has happened 6 times.