ComingSoon.net has posted the weekend box office estimates, which show that Green Lantern opened in first place with $52.6 million:
DC Entertainment's first major release based on a DC Comics character since its formation, Green Lantern (Warner Bros.), starring Ryan Reynolds, Blake Lively, Mark Strong, Peter Sarsgaard and Tim Robbins, opened relatively weak with an estimated $52.6 million, averaging $13.8k in 3,916 2D and 3D theaters. After doing more in Thursday midnights than the recent X-Men: First Class, it took in roughly $21.6 million on Friday but then had a substantial drop on Saturday, which doesn't bode well for any sort of long-term success.
You can read the full estimates by clicking here.