The Rock body-slammed the box office competition over the weekend as his popcorn flick, The Scorpion King, debuted at No. 1 with $36.2 million. The Mummy prequel set a record for the best opening weekend in April, besting the $27.8 debut of The Matrix in 1999. Last weekend's top grosser, Changing Lanes, slipped to No. 2 with a still-potent $11.1 million. Sandra Bullock's stinky thriller Murder by Numbers was pretty much DOA, taking in $9.5 million for third place. Rounding out the top five was The Rookie (No. 4 with $6.3 million) and Panic Room (No. 5 with $6.2 million).