leap to somebody's defence BrE
leap to somebody's defense AmE
jump to somebody's defence

Advocates of the French language leaped to the academy's defense.

So what if the felpurs hadn't leapt to his defense?

Now why had he leapt to her defense like that?

"I can't see why you're always so quick to leap to his defense after what he's done to you."

In the old days, the fighter would have leaped to his brother's defense.

Mikhail was glad to see they were alert and ready to leap to his defense.

Ash didn't leap to his defense as I'd expected her to.

The earlier resentment was forgotten as she leaped to her mother's defense.

"Trip, of course, leapt to my defense," she continued a moment later.

There were others with her, and they leapt to the woman's defense.