A week being a long time in football is among the oldest sayings in the book, but Mikel Arteta's Arsenal have found out it still rings true in the toughest way possible.
Seven days ago they were a win at Tottenham away from securing Champions League football for the first time since the 2016-17 season. Even a draw at their north London rivals would probably have been enough.
But a disastrous first half at the Tottenham Hotspur Stadium which saw an incredibly dubious penalty given and Rob Holding rightly sent off killed off any prospect of a derby classic.