The horror film starring Ethan Hawke surpassed industry expectations since the thriller only took $3 million to make.
"The Purge is set in the year 2022 when the United States is in a state of economic collapse. In the movie, people are allowed to commit crimes, including murder, for a period of 12 hours.
Vin Diesel's "Fast & Furious 6" held on to another strong week of ticket sales at the box office, dropping down to the No. 2 spot but earning $19.8 million over the weekend.
"Now You See Me" came in third, with $19.5 million.
The Google-promoting comedy "The Internship" starring Owen Wilson and Vince Vaughn debut with $18.1 million. "Epic" came in at No. 5.
The top 10 films of the weekend were:
1. "The Purge," $36.4 million.
2. "Fast & Furious 6," $19.8 million. ($45.3 million international).
3. "Now You See Me," $19.5 million ($2 million international).
4. "The Internship," $18.1 million.
5. "Epic" $12.1 million ($12.7 million international).
6. "Star Trek Into Darkness," $11.7 million ($17.6 million international).
7. "After Earth," $11.2 million ($45.5 million international).
8. "The Hangover Part III," $7.4 million ($34.8 million international).
9. "Iron Man 3," $5.8 million ($3.9 million international).
10. "The Great Gatsby," $4.2 million ($13.3 million international).
The Associated Press contributed to this report.
