In the second biggest four-day frame ever, three titles earned $60 million or more during the Memorial Day weekend — a box office first if estimates hold. “Star Wars: Episode III — Revenge of the Sith,” distributed by 20th Century Fox, led the way with $70.8 million in its second week. Comparing three-day spans, George Lucas’ sci-fi finale was down 49% against its opening. The movie’s total is a massive $271.2 million. On Sunday, “Sith” crossed the $500 million mark worldwide. “Madagascar” and “The Longest Yard” duked it out all weekend for second place, but in the end the CGI toon edged out the football remake, $61 million to $60 million. In fourth place for the frame was New Line’s “Monster-in-Law” with $11.1 million. The cumulative total on the Jennifer Lopez-Jane Fonda comedy is now $60.7 million. Universal’s “Kicking & Screaming,” also in its third week, was No. 5 with $6.6 million.