Wednesday's debut of "Transformers: Dark of the Moon" featured the biggest singular opening day of 2011 so far, $37.3 million.  Combined with the early showings of the Michael Bay actioner on Tuesday, the third installment in the "Transformers" franchise has now grossed $42.8 million in less than 48 hours.  It now ranks as the 6th biggest Wednesday opening day of all time and the 22nd biggest opening day ever.  That's clearly impressive for any film until you look at how its predecessor, "Revenge of the Fallen," performed just two years ago.

"Transformers: Revenge of the Fallen" was ridiculed by critics and most fans came away disappointed, but the Sci-Fi adventure still opened to a stunning $64 million - also on a Wednesday - en route to a massive $402.1 million cume.  Plus, this was without the added benefit of increased 3D ticket prices which has boosted "Dark of the Moon's" tally.

No one would expect "Dark of the Moon" to match "Revenge of the Fallen's" opening day (which ranks as the fourth biggest all time), but finding yourself behind the openers for "Alice in Wonderland," "X-Men: The Last Stand" and "Shrek Forever After", among others, has to concern the powers that be at Paramount.  Luckily, "Dark of the Moon" has received more favorable reviews than the last installment and faces little competition until "Harry Potter and the Deathly Hallows, Pt. 2" opens on July 15.

Look for continuing updates on "Transformers" box office run as well as the performances of Friday's new releases "Larry Crowne" and "Monte Carlo" all holiday weekend on HitFix.