There were plenty of moments which filled Arsenal with belief that this would be a historic season, like the 3-1 win over Bayern Munich in November in a battle of perfect records in the Champions League, or the 4-1 thrashing of Aston Villa around Christmas, or hammering Tottenham in both north London derbies, just because they could.
But Kai Havertz pinpoints a defeat, rather than a victory, as the catalyst for a season which has taken Arsenal to the Premier League title and the Champions League final in Budapest on Saturday.