How does White Fang accomplish his first victory over Lip- lip?

White Fang led Lip-lip in a chase.... straight into Kiche's jaws. When Lip-lip rolled loose, White fang attacked.

When at last he succeeded in rolling clear of her, he crawled to his feet, badly dishevelled, hurt both in body and in spirit. His hair was standing out all over him in tufts where her teeth had mauled. He stood where he had arisen, opened his mouth, and broke out the long, heart-broken puppy wail. But even this he was not allowed to complete. In the middle of it, White Fang, rushing in, sank his teeth into Lip-lip’s hind leg. There was no fight left in Lip-lip, and he ran away shamelessly, his victim hot on his heels and worrying him all the way back to his own tepee. Here the squaws came to his aid, and White Fang, transformed into a raging demon, was finally driven off only by a fusillade of stones.