What do I need to show for a "ticket" when I arrive in Shanghai?

Flight plan: USA -> PVG, stay for 3-day business meeting, PVG -> NRT

So based on this flight plan I think I can get the 144-hour VISA, correct? However, when I arrive in PVG I will not have the physical ticket for PVG->NRT (since airline only gives physical ticket when you check-in 24-hour before flight). So is showing my Airline Receipt and Itinerary with confirmation numbers good-enough at the 144-hr twov desk in Shanghai? Seat assignment for PVG->NRT may also be blank as seats normally are only assigned at book-in.