The first episode of this year's X Factor series was watched by 11.1m people on Saturday night, a significant increase on last year's figure of 9.9m.
The 90-minute opener, which featured the usual mix of genuine talent and deluded hopefuls, easily beat every other terrestrial rival.
At its peak, the ITV1 show was being watched by 12.6m people, nearly 50% of the total Saturday night TV audience.
In the same slot, BBC One variety show Tonight's The Night pulled in 3.3m.
Hospital drama Casualty, which was also scheduled against X Factor, was seen by an average audience of 3.8m, early overnight figures suggest.
The ratings are the highest-ever for an opening episode of the reality show.
However, ITV failed to maintain its lead, losing more than 6.5m viewers as X Factor handed over to game show Magic Numbers.
Now in its seventh series, The X Factor had to recruit a series of guest judges to cover for Dannii Minogue, who was on maternity leave during early stages of filming.
Saturday's auditionees were evaluated by former Spice Girl Geri Halliwell, alongside regular judges Simon Cowell, Cheryl Cole and Louis Walsh.
The show opened with Glaswegian house husband Stephen Hunter, who surprised the panel with his camp dance moves and unexpectedly soulful vocals on a version of The Trammps' classic Disco Inferno.
Other highlights included 18-year-old student Gamu Nhengu, whose interpretation of Walking On Sunshine defied Cowell's expectations.
"You sang one of my worst songs ever, but you did something different with it," he said.
"You've kind of got this really cool old school jazz voice, and I think you're really talented."
A trio named Jahm, who met online and believed themselves to be the next N-Dubz, were less successful. Their dissonant mauling of Lady Gaga's Bad Romance was met with stunned silence from the judges and the audience alike.
Reviews of the opening episode have been largely positive.
Writing in the Daily Mail, Sarah Bull highlighted the show's "inventive and entertaining performances".
Sky News called the X Factor a "grand panto", but the Daily Telegraph criticised the reality giant's lack of evolution.
"It might have been an episode from 2009," wrote TV critic Michael Deaton.
"And yet," he added, "for all its predictability and its punishing length, Saturday's episode rarely felt tired."
Last year's series was won by Joe McElderry.