。
She slapped him in the face.
Literal
She [topic-は] his [genitive-の] face [object-を] slapped.
ひっぱたく ('slap, strike, smack') is a 複合動詞 — historically 引く ('pull') + 叩く ('hit') — though now mostly written in kana. Conveys a quick, sharp strike with the open hand. Compare with the more general 叩く ('hit, strike') and the noun 平手打ち ('slap'). The colloquial、almost violent flavor.