A blockbuster lineup featuring the premiere of the second Harry Potter movie, The X Factor and I'm A Celebrity helped ITV1 to its best Saturday performance in almost four years at the weekend.

The channel recorded an average primetime share of 40.7%, a figure not passed since the final of the inaugural series of Pop Idol in February 2002.

Beginning the lineup was the much-publicised premiere of Harry Potter and the Chamber of Secrets, which averaged an impressive 7.99 million viewers - a 37.3% share of the audience - between 5.15pm and 8pm.

The X Factor performances show, pushed back to a later slot, improved to 9.68 million (41.6%) in the 8pm hour. A 90-minute episode of I'm A Celebrity interested 9.57 million (41.6%) from 9, before a later-than-usual X Factor results show drew 8.85 million (43.7%) to close off prime.

BBC One maintained an admirable defence throughout, peaking with 9.57 million (40.9%) for the performances episode of Strictly Come Dancing between 6.25pm and 7.40pm. The National Lottery: Millionaire Manor debuted to 6.99 million (30.3%) over the next 40 minutes before Casualty took a hit, dropping to 6.53 million (27.8%) and eighth place for the day.

The Strictly Come Dancing results show also lost viewers, averaging 6.62 million (27.7%) between 9.10pm and 9.40pm.

A CSI: Crime Scene Investigation repeat helped Five to victory amongst the minor terrestrials, averaging 2.12 million (9.2%) from 9.10pm. Law and Order: Criminal Intent had a respectable 1.75 million (8.4%) in the following hour. Channel 4's latest Jimmy Carr-fronted countdown show, The Comedians' Comedian, also fared well with 1.61 million (8.3%) between 9pm and midnight.

As usual, BBC Two was left in the shade with its lineup of Bodies (0.89 million, 3.8%) and Family Guy (0.66 million, 3%).

Sky Sports 1's coverage of the game between Liverpool and Wigan Athletic topped the multichannel chart, drawing an average of 856,000 (12.6%) between midday and 3pm.

The Xtra Factor Result pulled in 699,000 (5.6%) for ITV2, despite airing in a later, 11pm timeslot. Spinoff show I'm a Celebrity Get Me Out of Here - NOW! followed with 262,000 (3.1%).

Other strong multichannel performers included the Sky Movies premiere of Catwoman (244,000 + 262,000, 1.4%), ITV3's Inspector Wexford (424,000, 2.6%) and BBC Three's Unfaithful (177,000, 1.1%).