Has an AFL game ever ended 51-49?
Yes. AFL has seen a final score of 51-49 3 times. It first happened on June 9, 1923, when Sydney beat Carlton, and most recently on March 22, 2008, when St Kilda beat Sydney.
That makes 51-49 the 1534th most common final score out of 6,607 that have ever occurred in AFL. One point away, 52-49 has happened 3 times and 51-50 has happened 1 times. At one point the score disappeared for 81 years, between 1923 and 2004.