Denzel Washington and Russell Crowe star in the 1970s saga about a detective on the tail of a Manhattan-based heroin kingpin.
Bee Movie, voiced by Jerry Seinfeld and Renee Zellweger among others, opened in second place on $39.1m and is about a bee that decides to sue humans when he learns that they eat honey.
The robust start to November reversed a six-week slide as the top 12 films grossed $143m and climbed 11% against the same weekend in 2006.
The only other new entry was New Line's drama The Martian Child starring John Cusack in seventh place on $3.7m. Cusack plays a man who adopts a strange child that may be an alien. Amanda Peet and Bobby Coleman also star.
Lionsgate's Saw IV fell to third place on $11m for $51.1m after two weekends, and Buena Vista's romantic comedy Dan In Real Life slipped to fourth on $8.1m for $22.9m after the same amount of time.
Sony's 30 Days Of Night ranks fifth on $34.2m after three, while Buena Vista's family hit The Game Plan has amassed $81.9m and ranks sixth after six.
Next weekend's wide releases are: Lions For Lambs, the revitalised UA's first release under the Paula Wagner-Tom Cruise leadership that stars Cruise, Meryl Streep and Robert Redford and is being released through MGM; and Warner Bros' comedy Fred Claus with Vince Vaughn and Paul Giamatti.
Estimated Top 10 North America Nov 2-4, 2007
Film (Dist)/Int'l dist/Est wkd gross/Est total to date
1 (-) American Gangster (Universal) UPI $46.3m -
2 (-) Bee Movie (Paramount-DreamWorks) PPI $39.1m -
3 (1) Saw IV (Lionsgate) Mandate Int'l $11m $51.1m
4 (2) Dan In Real Life (Buena Vista) Focus Features International $8.1m $22.9m
5 (3) 30 Days Of Night (Sony) Mandate Int'l $4m $34.2m
6 (4) The Game Plan (Buena Vista) WDSMPI $3.9m $81.9m
7 (-) The Martian Child (New Line) NLI $3.7m -
8 (6) Michael Clayton (Warner Bros) Summit Int'l $2.9m $33.1m
9 (5) Why Did I Get Married' (Lionsgate) Mandate Int'l $2.7m $51.2m
10 (7) Gone Baby Gone (Miramax) WDSMPI $2.4m $14.9m