Has an AFL game ever ended 52-51?
Yes. AFL has seen a final score of 52-51 7 times. It first happened on June 22, 1901, when Geelong beat Fitzroy, and most recently on June 27, 2020, when Carlton beat Essendon.
That makes 52-51 the 222nd most common final score out of 6,649 that have ever occurred in AFL. One point away, 53-51 has happened 5 times and 52-52 has happened 2 times. At one point the score disappeared for 57 years, between 1962 and 2019.