That gives the metal man the third biggest opening week gross of any film launching the summer movie season. Only its Marvel Comics siblings Spider-Man 3 and Spider-Man have done better among those movies with $182.1M in 2007 and $151.6M in 2002, respectively.

Iron Man's first-week tally actually matches the opening week total of 2003's X2: X-Men United when adjusted for today's ticket prices. That super hero sequel banked $107.6M in its first seven days in early May 2003 which would translate to roughly $127M at 2008 prices.

The Robert Downey Jr. smash now begins its second weekend in theaters and even with a sizable 50-55% decline, it would still break through the $170M mark by the end of the frame. A final trajectory meeting or exceeding the $250M level seems likely.