It started at 100 miles an hour and although Mayo drew first blood, the big talking point so far has undoubtedly been Joe McQuillan's decision to award Dublin a penalty after David Drake's foul on Paul Flynn. Diarmuid Connolly duly slotted home but the decision was a contentious one.
It was certainly a foul but whether it was inside the line is very debatable. We'll leave it here and you can take a look for yourself.
The early reaction to the decision has been rather negative.
Hometown decision - not even inside..... pic.twitter.com/Gif3IbA6t5
— Declan Varley (@declanvarley) August 30, 2015
He was outside
— Eddie Brennan (@NedzerB13) August 30, 2015
outside the square and minimal contact but some finish from connolly
— Kieran O'Brien (@KOBrien1977) August 30, 2015