Shrek The Third had a fairy tale beginning at the North American box office this weekend, grossing an estimated $122m and beating Shrek 2's record for the biggest ever opening by an animated film.

The DreamWorks Animation CG outing becomes the third biggest domestic opener of all time, behind only this month's Spider-Man 3 and last year's Pirates of the Caribbean: Dead Man's Chest.

Distributed by Paramount, the third installment in the massively successful franchise about the big green ogre and his friends opened in 4,122 theatres, for a per-theatre average of $29,597. When limited Thursday night showings are included the film's estimated box office total becomes $122.9m.

Shrek 2 opened in a similar mid-May slot in 2004 and grossed $108m over its first weekend from 4,163 screens (thanks to a Wednesday opening it ended the weekend with $128.9m). It went on to take $441.2m domestically and $920.7m worldwide.

Whether the third outing - in which Justin Timberlake joins the voice cast led by Mike Myers, Eddie Murphy, Cameron Diaz and Antonio Banderas, and Chris Miller takes over as director - can beat those totals will depend on how well it stands up to competition from potential record breaker Pirates of the Caribbean: At World's End, which opens for the coming holiday weekend.

Shrek The Third withstood competition from the two-week-old Spider-Man 3 better than expected. Some pundits thought Spidey would entrap some of Shrek's audience, but the DreamWorks offering, which got mixed reviews, benefited from its short running time and ultra-wide release (though it also suffered from the fact that many tickets were sold to children at reduced prices).

After falling 62% last weekend, Sony's Spider-Man 3 dropped 51% in its third weekend, taking an estimated $28.5m from 4,324 theatres, for an average of $6,591 and a total to date of $281.9m.

Fox's 28 Weeks Later, which opened behind Spider-Man 3 last weekend, dropped a reasonable 47% to $5.15m from 2,305 theatres (average - $2,234), for a total of $18.6m.

Hanging on to fourth place on the chart in its sixth weekend, Paramount's Disturbia, also from DreamWorks, had another strong holdover, sliding only 22% to $3.7m from 2,547 theatres (average - $1,443). The thriller has now racked up a domestic total of $71.3m.

Universal's Georgia Rule, which opened last week behind 28 Weeks, fell 48% to $3.5m from 2,531 theatres (average - $1,380), for a $12.6m total.

New Line's Fracture was the top ten's second sturdy thriller, sliding 17% to $2.5m from 1,607 theatres (average - $1,531) for a $34.7m total.

Lionsgate's Delta Farce, the third of last week's new releases, was off 46% to $1.8m from 1,931 theatres (average - $953). The broad comedy's total went to $6.1m.

In the remainder of the top ten, Focus Features' British comedy Hot Fuzz was off only 27% in its fifth week, taking an estimated $1.2m from 973 screens (average - $1,290) for a $21.1m total to date.

Fox Searchlight's promising comedy Waitress, written and directed by the late Adrienne Shelly and starring Keri Russell, entered the top ten with a 73% third-week jump to $1.1m after almost doubling its theatre count to 116. Its $9,784 average was the second highest among the top ten and pushed the film's total to $2.2m.

Next weekend's wide releases are: Buena Vista's Pirates of the Caribbean: At World's End, third installment in the massively successful family adventure series, with Chow Yun Fat joining cast regulars Johnny Depp, Keira Knightley, Orlando Bloom and Geoffrey Rush, and Gore Verbinski again directing; and Lionsgate horror thriller Bug, with William Friedkin directing Ashley Judd.

Estimated Top 10 North America May 18-20, 2007

Film (Distributor)/International distribution/Estimated weekend gross/Estimated total to date

1 (-) Shrek The Third (Paramount) PPI $122m -

2 (1) Spider-Man 3 (Sony) SPRI $28.5m $281.9m

3 (2) 28 Weeks Later (Fox) Fox Intl $5.15m $18.6m

4 (4) Disturbia (Paramount) PPI $3.7m $71.3m

5 (3) Georgia Rule (Universal) Morgan Creek Intl $3.5m $12.6m

6 (6) Fracture (New Line) NLI $2.5m $34.7m

7 (5) Delta Farce (Lionsgate) Lionsgate $1.8m $6.1m

8 (7) The Invisible (Buena Vista) BVI $1.3m $17.7m

9 (10) Hot Fuzz (Rogue Pictures) UPI $1.2m $21.1m

10 (-) Waitress (Fox Searchlight) Fox Intl $1.1m $2.2m