Until the two Mercedes drivers reached the end of the Kemmel Straight and turned into the Les Combes right-hander on lap two of the Belgian Grand Prix, the conflict between Lewis Hamilton and Nico Rosberg was a cold war.
There had been flashpoints, games of brinksmanship, suspicions, hostility and a growing atmosphere of distrust, but this was the moment when the warning shots stopped and the live ammunition was used for the first time.
Debates will rage over who really started this conflict, and exactly when. But the one indisputable fact is that it was Rosberg who fired the first shot on track. And from a world championship perspective, it hit the spot perfectly, putting his title rival out of contention - even if Rosberg himself lost a chunk of his front wing, and possibly a chance of victory, in collateral damage.