Warner Bros.’ “Superman” retained the top spot at North American cinemas with an estimated $24.9 million in weekend ticket sales, bringing its domestic total to $289.5 million. International receipts of $19.8 million lifted the comic-book epic’s worldwide gross to $502.7 million, making it the second film released this summer to clear the half-billion-dollar threshold. Paramount’s “Smurfs” placed a distant second, collecting $5.4 million for a $22.8 million domestic tally, while overseas markets added $11.2 million to push its global haul to roughly $69 million. Sony’s horror reboot “I Know What You Did Last Summer” followed closely with $5.1 million, bringing its domestic total to $23.6 million after a steep 60 percent drop in its sophomore frame. Universal and DreamWorks Animation’s “How to Train Your Dragon” slipped to $2.8 million at home but crossed $600 million worldwide after generating $5.2 million internationally; the $150 million production now stands at $605.9 million globally, including $257.0 million in North America. Indie distributor A24 saw muted results. Ari Aster’s “Eddington” fell 61 percent in its second weekend to $1.7 million for an $8.1 million domestic cume, while romantic drama “Sorry, Baby,” expanded to 338 locations, earning just $0.4 million for $1.6 million to date.