Iron Man 2 (Tribute viewer rating: 4.1 stars out of 5) starring Robert Downey Jr. soared to the top spot at the US box office with an estimated take of $128 million and an incredible worldwide gross of $322 million in its first weekend. The sequel outperformed the original, which collected $96 million when it debuted in May 2008, making the sequel the fifth highest grossing movie debut of all time. Its competition lagged far behind, with no other film even breaking the $10 million mark. Last week’s top movie, A Nightmare on Elm Street (TVR: 2.7), was far behind in second place, earning $9.1 million. How to Train Your Dragon (TVR: 4.6), earned an additional $6.7 million in third place, topping the $2 million mark in its seventh weekend. Date Night (TVR: 4.1), starring Steve Carrell and Tina Fey, slipped a spot to No. 4, grossing $5.4 million, while The Back-Up Plan (TVR: 3.6) starring Jennifer Lopez, rounded out the top five with $5 million. In Canada, Iron Man 2 was also the No. 1 movie, while How to Train Your Dragon placed second; A Nightmare on Elm Street was in third place; The Back-Up Plan was in fourth; and Furry Vengeance managed to squeak into the top five as well.