It may feature a man having his nipple bitten by a baby crocodile but Jackass: The Movie's constitution did not prove strong enough to unseat The Ring at the UK box office last week.

But Jackass, which entered the chart at number two, still made a remarkable assault on UK cinemas with a three-day gross of $2m. The adaptation of MTV's outlandish cult gross-fest, which had an unexpectedly large opening in the US last year, opened in the UK on 340 sites to an average of $6,118 per site for distributor UIP.

The Ring, another UIP release, held onto the number one spot with a three day gross of $2.7m, for a good site average of $6,727. That's a 23% drop-off from its opening, but gives The Ring a $20.6m gross from two weeks on release. The horror remake is directed by Gore Verbinski and stars Naomi Watts, Martin Henderson and Brian Cox.

Analyze That, the only other new entrant in the top ten apart from Jackass, saw a so-so opening that was only enough to place it at number eight in the chart for Warner Bros. The Billy Crystal, Robert De Niro and Lisa Kudrow-starring follow-up to Analyze This banked a three-day gross of only $827,000, with a per-site average of $2,852.

Neither of this week's other major openers managed to bother the top ten. Steven Soderbergh's arty Solaris, starring George Clooney, opened at number 12 for Fox, with a three day gross of $497,000 from 153 sites. And Spike Jonze's Adaptation, released by Columbia TriStar, debuted at number 14 in the chart, despite critical support. The film took a three-day gross of $378,000 from only 94 sites, for a good site average of $4,021.

Chicago, riding high on the publicity generated by Catherine Zeta-Jones's best supporting actress Bafta win saw a week-on week drop-off of only 10%. With a three-day gross of $884,000 the film holds itself steady at number seven in the chart after 10 weeks on release for distributor BVI.

The Hours, another BVI release heavily publicised in the UK after Nicole Kidman's best actress Bafta win dropped only one place in the chart to number 10 on its third week on release. The film has so far grossed $4m in the UK.

UK admissions showed an upbeat start to the year, according to the Cinema Advertising Association, with 16.3m cinema admissions during January. The month posted an increase of 8% year on year to make the largest January total since 1971. The top five films during the month were The Lord Of The Rings: The Two Towers, 8 Mile, Gangs Of New York, Chicago and Star Trek X: Nemesis.