The jolly green giant may have vanquished all box office foes but this 4th outing couldn’t beat its ultimate competitor- itself. The DreamWorks animated sequel, which was released in 3D at more than half of its 4,359 locations, earned $71.3 million in the U.S. and Canada. The audience was well below previous Shrek films, including Shrek the Third, which opened at $121.6 million in May 2007. Looks like 4th time was not the charm. Marvel’s Iron Man 2 came in second with $26.6 million while Robin Hood came in third with $18.7 million, bringing its North American total to $66.1 million. Saturday Night Live spin-off, MacGruber took in a meager $4.1 million during it’s opening weekend, landing in sixth position missing our top 5.