Channel 4 attracted a higher audience share than BBC2 in 2005, the first time it has done so in a decade. Ratings winners such as the Ashes cricket coverage, Jamie's School Dinners and the blockbuster drama Lost helped Channel 4 to achieve an overall share of 9.7 per cent of viewers over the past year, compared with BBC2's 9.4 per cent average.
It was the only the third time since its launch 23 years ago that Channel 4 has beaten BBC2 over a 12-month period.
A spokesman for Channel 4 said "outstanding creative strength" had led to its triumph. Other hit shows included Desperate Housewives, the sixth series of Big Brother and Supernanny.
Channel 4 increased the proportion of its younger viewers aged 16 to 34 to 8 per cent during peak viewing time, and took a higher share of the ABC1 audience than BBC2. The independent channel has maintained its overall audience share over the past year, but BBC2's has fallen 6 per cent.
Kevin Lygo, Channel 4's director of television, had predicted triumph over his rival when he launched his winter schedule last month. "It has been a brilliant year," he said. "I don't know whether it's because of our brilliance or because the BBC has been seeking charter renewal like an Exocet."
The broadcaster's latest spin-off channel, More4, has established a 0.5 per cent audience share since its launch two months ago.