However, Tropic was widely expected to open smaller since it skews a bit older and is likely to see more of its target audience wait until the weekend before heading to the multiplexes. Pineapple had more appeal to high school and college students who are out of school and more available midweek to go to the movies. Tropic cost more than three times as much to produce with a budget of $90M compared to the Judd Apatow pic's $27M negative cost.

Also starring Jack Black and Robert Downey Jr., the Hollywood farce should rake in somewhat more than $10M over the Wednesday-Thursday span before heading into the Friday-to-Sunday period. The studio is hoping that good word-of-mouth from initial audiences will help to fuel interest this weekend.

Ten years ago, Stiller's R-rated comedy There's Something About Mary also debuted in the summer on a Wednesday. That sleeper hit grossed $4.1M in its first two days representing 23% of the $17.8M five-day debut. Given how movies are more front-loaded today, it could mean that Thunder might reach $35-40M over its five-day opening weekend.

The Dark Knight captured another $3M on Wednesday upping its cume to $451.9M allowing it to break the $450M mark in just 27 days. Warner Bros. may end up losing the top spot this weekend after a four-week rule, but it does expect to soar higher than $470M by Sunday night.

All-Time Domestic Blockbusters list - UPDATED