After a week of ruling the international box office, it looks like Marvel has another Hulk-sized domestic box office hit on their hands.

"Iron Man 3" opened in North America this weekend, flying to a massive $68.3 million on Friday, and is a shoo-in for one of the biggest opening weekends in box office history.

Box office prognosticators are betting that "Iron Man 3" will likely pick up north of $165 million for the three-day (including Thursday's late night showings). 

The film, Starring Robert Downey Jr. as the title hero, will easily become either the No. 2 or No. 3 biggest domestic opener of all time. As of now, "The Avengers" (also featuring Downey Jr. as Iron Man) holds the top spot with $207.4 million, while "Harry Potter and the Deathly Hallows, Part 2" is at No. 2 with $169.2 million, with "The Dark Knight Rises" at No. 3, with $160.9 million.  

"Iron Man 3" opened week ago at the international box office, and its global total already stands at a heroic $456.6 million. While it won't top "The Avengers" at the domestic box office, the threequel is beating the 2012 superhero saga internationally. 

"Iron Man 3" is also well ahead of "Iron Man 2's" opening numbers. That film made $51.2 million on its first Friday, and earned $128.1 million for opening weekend.

With the latest Marvel superhero extravaganza taking the lion's share of the box office, several holdovers continued to do solid business. 

Michael Bay's comedy "Pain and Gain" placed at No. 2, muscling up another $2.3 million. It has so far bulked up to a decent $28.6 million. 

The Jackie Robinson biopic "42," which scored $1.7 million on Friday, bringing its total to $73.9 million. 

Tied for third place, the Tom Cruise sci-fi film "Oblivion" also netted $1.7 million. The Joseph Kosinski-directed film's domestic total stands at $71.8 million. 

The struggling family comedy "The Big Wedding" earned $1.2 million on Friday, for a total gross of just $11.5 million so far.

Look for complete weekend estimates tomorrow on HitFix.