Definition of "flashpoint"

Chances came and went at both ends before the flashpoint involving Vardy and Nasri, who took an age to leave the pitch after Daniele Orsato, the Italian referee, brandished a red card.

2017 March 14, Stuart James, “Leicester stun Sevilla to reach last eight after Kasper Schmeichel save”, in the Guardian‎

In a match which contained several flashpoints in the crowd, including loud jeering when England's players took the knee before kick-off, objects being thrown and racist chanting, they came through a mediocre first half to take total control after the break and run out easy winners.

2021 September 2, Phil McNulty, “Hungary 0-4 England”, in BBC‎