LOS ANGELES -- "Speed Racer" was lapped in its opening weekend at the box office as "Iron Man" continued to fire its jets with $50.5 million in ticket sales, according to studio estimates yesterday.

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" would have difficulty recouping its $120 million budget.

"Unfortunately it didn't perform to our expectations," he said.

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

Revenue for Marvel Studios' "Iron Man" slipped just 49 percent in its second week in theaters, a respectable showing considering its massive opening.

BOX OFFICE: Estimated ticket sales in millions for Friday through yesterday at U.S. and Canadian theaters, according to Media By Numbers LLC.

1. "Iron Man" $50.5.

2. "Speed Racer" $20.2.

3. "What Happens in Vegas" $20.

4. "Made of Honor" $7.6.

5. "Baby Mama" $5.8.

6. "Forgetting Sarah Marshall" $3.8.

7. "Harold & Kumar Escape from Guantanamo Bay" $3.2.

8. "The Forbidden Kingdom" $1.9.

9. "Nim's Island" $1.3.

10. "Redbelt" $1.1.