One Piece Chapter 46, page 17: The Uninvited Guest

Just as Patty finishes his warning, Don Krieg, now fully re-energized by the meal, suddenly strikes Sanji with a brutal backhand blow. The impact sends Sanji flying backward across the restaurant floor. Gin screams in horror, "Sanji!" while Luffy, the cooks, and the customers watch in absolute shock at the immediate betrayal.