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 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.

“Our tracking was stalled toward the end,” said Dan Fellman, president of Warner Bros. theatrical distribution, about market surveys before the “Speed Racer” opening.

Fellman added “Speed Racer” would have difficulty recouping its $120 million budget. “Unfortunately it didn’t perform to our expectations,” he said.

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.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Media By Numbers LLC:

1. “Iron Man,” $50.5 million.

2. “Speed Racer,” $20.2 million.

3. “What Happens in Vegas,” $20 million.

4. “Made of Honor,” $7.6 million.

5. “Baby Mama,” $5.8 million.

6. “Forgetting Sarah Marshall,” $3.8 million.

7. “Harold & Kumar Escape from Guantanamo Bay,” $3.2 million.

8. “The Forbidden Kingdom,” $1.9 million.

9. “Nim’s Island,” $1.3 million.

10. “Redbelt,” $1.1 million.