Gatsby looks almost as great as a superhero at the weekend box office.

Leonard DiCaprio’s “The Great Gatsby” partied like it was the Roaring ’20s with a $51.1 million debut that made it a surprisingly strong runner-up to comic-book blockbuster “Iron Man 3.”

Studio estimates Sunday put “Gatsby” at No. 2 behind Robert Downey Jr.’s superhero sequel, which pulled in $72.5 million domestically to raise its total to $284.9 million after just 10 days in U.S. theaters.

The weekend’s other new wide release, Lionsgate’s romantic comedy “Peeples,” flopped at No. 4 with just $4.9 million. Produced by Tyler Perry, the movie stars Craig Robinson and Kerry Washington in a meet-the-parents-style farce.

Getting a head start on its domestic launch Friday, “Star Trek: Into Darkness” opened with $31.7 million in seven international markets. Its overseas debut included $13.3 million in Great Britain, $7.6 million in Germany and $5.5 million in Australia.

Starring DiCaprio in the title role as 1920s mystery millionaire Jay Gatsby, the latest Fitzgerald update co-stars Carey Mulligan as his lost love and Tobey Maguire as the friend chronicling their doomed romance.