Low-budget comedy Barbershop has taken $21m (�13.6m) at the US and Canadian box office in its opening weekend to secure the top spot, according to studio estimates.

Ice Cube plays the owner of a neighbourhood barber shop who allows it to slip into the hands of a loan shark, only to realise it is a pillar of his community.

The audience for the gentle comedy is 70% black and mostly under the age of 35, MGM marketing president Peter Adee said.

Top five

1. Barbershop 2. My Big Fat Greek Wedding 3. One Hour Photo 4. Stealing Harvard 5. Swimfan Source: Exhibitor Relations

Starring comedian Cedric the Entertainer and rapper Eve, the film is a welcome hit for MGM, which has had a string of disappointments this year including Windtalkers, Hart's War and Rollerball.

A sequel could follow on a bigger budget than Barbershop's modest $12m (�7.8m).

Once studio estimates are confirmed on Monday, Barbershop will have the third best September debut, after Rush Hour with $33m (�21.4m), Double Jeopardy $23.2m (�15m) and ahead of Remember the Titans $20.9m (13.5m).

The film easily outperformed "sleeper hit" My Big Fat Greek Wedding, which is on its way to breaking records for an independent film.

The tale of the chaotic build-up to Greek-American nuptials spent a third weekend at number two and is now well over the $100m (�64.7m) mark with its $11m (�7.1m) taking it $110.7m (�71.7m) after five months on release.

The phenomenon cost only $5m (�3.2m) to make.

Swimfan lost ground in its second week

Robin Williams psychological drama One Hour Photo rose 10 places to number three with $7.7m (�5m) after its release went nationwide.

The strong performances meant the total gross for the top 12 films was up by 38% over the corresponding weekend last year to $72m (�46.6m), according to tracking firm Exhibitor Relations.

Comedy Stealing Harvard was the only other new entry in the top 10, making its debut at number four with $6.3m (�4.1m).

Teen thriller Swimfan fell to number five with $6.1m (�4m) after claiming the top spot last week.

New releases next weekend include another remake of the 19th Century drama The Four Feathers, the spy thriller Ballistic: Ecks vs Sever, the kidnap thriller Trapped, and the middle-aged groupie comedy The Banger Sisters.