"Iron Man" continued to fire its jets with $50.5 million in ticket sales, passing up "Speed Racer" in the latter's opening weekend, according to studio estimates Sunday.

The anime-inspired race movie edged into the No. 2 spot with $20.2 million, slightly ahead of the 20th Century Fox comedy "What Happens in Vegas," which debuted at $20 million.

Dan Fellman, president of Warner Bros. theatrical distribution, said "Speed Racer" will have difficulty recouping its $120 million budget.

"Speed Racer" was panned by many film critics and was made by the Wachowski brothers, best known for the "Matrix" franchise.

"What Happens in Vegas," a romantic comedy that cost $35 million and stars Cameron Diaz and Ashton Kutcher, shot the gap between the action flicks, said Chris Aronson, senior vice president at 20th Century Fox.

"We come along with a character-driven movie in what is now considered summer, and it's just a great result," Aronson said.

Five of the top 10 grossing movies were comedies. The weekend's total domestic box office gross hit $128 million, up 21 percent from last year. But year-to-date revenue was still down 2.5 percent at $2.93 billion, while attendance was off 5.3 percent.

Over the next few weeks, several big movies will take a shot at knocking "Iron Man" off its perch, starting with "The Chronicles of Narnia: Prince Caspian," opening Friday, and "Indiana Jones and the Kingdom of the Crystal Skull" on May 22.