Arriving in Beijing by Trans-Siberian Train from Moscow, flying to US the same day. Free Transit ok?

The Trans-Siberian train from Moscow crosses the Chinese border in Erlian at 01:20hrs (passport formalities during the brief stop at the train station) and arrives in Beijing at 11:40hrs (10hrs,20 min later). My flight to USA is scheduled from Beijing at 15:45hrs that same day. Do I need to apply for an entry permit OR can I just present my flight ticket to the authorities upon entering PRC without worrying about a visa?
Thank you.