Actor Robert Downey Jr. gives a high-five to his "Iron Man" character during opening bell ceremonies of the New York Stock Exchange, Tuesday, April 30, 2013. Downey's film, "Iron Man 3," also starring Don Cheadle and Gwyneth Paltrow, opens nationwide on May 3. This undated publicity photo released by Marvel shows Robert Downey Jr. as Tony Stark/Iron Man in a scene from Marvel's "Iron Man 3." The movie releases in the USA on May 3, 2013. (AP Photo/Marvel, Zade Rosenthal) LOS ANGELES (AP) - Iron Man is a bigger golden boy than ever with a $175.3 million opening weekend at the domestic box office for the superhero's latest sequel. According to studio estimates Sunday, "Iron Man 3" had the second-biggest debut ever, behind the $207.4 million start last year for "The Avengers," which teamed him with other Marvel Comics heroes. Opening a week earlier overseas, "Iron Man 3" has hauled in $504.8 million internationally, giving the blockbuster a worldwide total of $680.1 million. The film shot past the $312 million international total for "Iron Man 2" in its entire theatrical run. "Iron Man 3" far outpaced the franchise's first two movies. "Iron Man" launched the series with a $98.6 million domestic debut in 2008, while 2010's "Iron Man 2" opened with $128.1 million.