Sheffield Wednesday's FA Cup visit to Highbury in 1999 was marred by a bizarre incident of misunderstanding.
Blades keeper Alan Kelly put the ball out of touch so one of his teammates could receive treatment. Ray Parlour intended to return the ball from the throw-in, but debutant Nwankwo Kanu misread the situation and set up Marc Overmars for a highly controversial goal.
When the game ended 2-1, Arsene Wenger made the sporting gesture of offering a replay of the match. The offer was accepted, and 10 days later, the Gunners inflicted another 2-1 defeat.
Wenger, a man whose default reaction is to claim he hasn't seen a controversial incident, earned a FIFA Fair Play trophy for his troubles.