Thanks to a hearty $31 million seven-day run in China, Warner Bros.’ “The Dark Knight Rises” claimed nearly $50 million internationally, boosting the film past the $1 billion mark worldwide. Sony’s “The Amazing Spider-Man,” however, narrowly won Chinese bragging rights, with its $32.5 million local opening.The pair went to head-to-head on the mainland, bowing locally Aug. 27. (China frequently programs Hollywood blockbusters against each other to reduce their overall impact on local films.) China Film Group scheduled a similar showdown last week, dating Fox’s “Prometheus” for Sept. 2, followed only two days later by “The Expendables 2″ via local distrib Le Vision. “Prometheus” earned $4.2 million opening day, while “Expendables 2″ scored $3.5 million locally. In the Batman-Spidey scrimmage, total box office offers only part of the picture in China: The 2D-only “Dark Knight Rises” actually scored more admissions than “Spider-Man,” which benefitted from higher 3D ticket prices. “Rises” also had fewer screens overall in the territory, 4,081 vs. 7,125. The opening Chinese gross for “The Amazing Spider-Man,” which surpassed the entire local cume of “Spider-Man 3,” lifted the reboot’s international total to $474.5 million, for an impressive global haul of $735 million. Sony’s newest Spidey pic now stands as the year’s fourth highest-grossing release, behind billion-dollar pair “The Avengers” and “Dark Knight Rises,” as well as Fox’s “Ice Age: Continental Drift,” which reached $833 million globally through Sept. 4. With Italy still to come Sept. 28, “Drift” should end up surpassing the overseas cume of its “Ice Age” predecessor, “The Meltdown” ($693 million), to become the highest-grossing animated film internationally. “Meltdown” earned $45 million at the Italo B.O. in 2008.