Schwimmer makes his directorial film debut in Fatboy

The film, which was directed by former Friends star David Schwimmer, has now taken more than �4.5m beating new release Superbad into second place.

Oscar hopeful Atonement, based on the best-selling book by Booker nominee Ian McEwan, dropped one place to number three this week.

The Bourne Ultimatum, starring Matt Damon, fell to number four.

Pegg, who also appeared in Hot Fuzz, co-wrote Run, Fatboy, Run, which sees him playing an overweight security guard trying to win back the girlfriend he abandoned at the altar five years before.

UK BOX OFFICE 1. Run, Fatboy, Run - �1.5m 2. Superbad - �1.4m 3. Atonement - �1.3m 4. The Bourne Ultimatum - �744,851 5. Disturbia - �728,145 Source: Screen International

The comedy, which was Schwimmer's first film he directed, also features Simpsons star Hank Azaria and comedian Dylan Moran.

Thriller Disturbia made its debut in the chart at number five, while US comedy Knocked Up followed at six.

Two more new releases that made it into the top 10 were Shoot 'Em Up and former US number one 3:10 to Yuma, which reached number seven and eight respectively.