21 tops the weekend box office charts, according to studio estimates released on Sunday. The casino caper earned a healthy $23.7 million -- almost $9,000 per theater -- to leave it well clear of Horton Hears a Who, which had a very satisfying third weekend with $17.4 million, a fall of just 29%. Consider last weekend was Easter, that's a very impressive performance.

Superhero Movie and Stop-Loss each performed about in line with expectations. The spoof picked up an estimated $9.5 million, while the Iraq drama scored around $4.5 million. Both earned a per theater average of approximately $3,500.

The weekend's biggest disappointment was British comedy Run, Fat Boy, Run, which opened with $2.4 million in 1,133 theaters for an average a slightly over $2,000 -- not enough to stand a chance of significant expansion.

- Weekend Estimates

Date posted: 2008-03-30