Having successfully completed a task by yourself.

i.e. Having won a match of search and destroy without the assistance of your team

When you see your friends being Clutch so you call out Clutch or Be Clutch.

When you are playing an online game , and you are the only one alive on your team.You have to "Clutch"the round by killing the opposing team single-handedly. So clutching is surviving in a one versus five or more players situation, killing them and winning the game . Clutching a situation in other words is getting control over a close situation.

When you are flashing a strap but don't pull the trigger or shot to kill.

Clutch; - Perfect, Exactly what is needed, (also used like "score" or "awesome", as an exclamation.)

Exactly what you need, exactly when you need it.

to perform under pressure