奋勇当先 (fèn yǒng dāng xiān): To bravely take the lead in a difficult or dangerous task — Meaning & Stroke Order

This firefighter bravely took the lead and rushed into the burning building to rescue the child.

Every time the team encounters difficulties, he always bravely takes the lead and never backs down.

In the environmental protection activity, the volunteers bravely took the lead and cleaned up a large amount of trash.

Faced with injustice, he bravely took the lead and stood up to speak for the weak.