ITV's X Factor was seen by an average audience of 9 million people on Saturday night, ahead of the figure for Strictly Come Dancing's launch.
The BBC's show was watched by an average of 8 million people, although the two programmes were not scheduled against one another.
At its peak, however, Strictly was seen by 9.8 million - slightly higher than X Factor's peak audience of 9.5 million.
Strictly's peak came at 19:30 and was the highest TV audience of the day.
The returning dance competition saw this year's celebrities paired with their professional dance partners.
Olympic cyclist Victoria Pendleton will dance with the show's "bad boy" Brendan Cole, while TV presenter Johnny Ball will be trained by last year's winner Aliona Vilani.
Silver medal-winning gymnast Louis Smith was installed as the bookmakers' favourite after Saturday's introductory show, in which he performed a standing backflip.
He will dance with one of the show's most popular professionals, Flavia Cacace.
The audience figures gave the programme its highest debut since 2009 when it pulled in 8.4 million, although the programme was scheduled differently then and started with a Friday show.
Meanwhile, the X Factor's 9 million-strong audience was its highest so far this year - but could not compare with the corresponding show from 2011, which had 11.1 million viewers.
This weekend marks the end of the reality series' audition stages, with action progressing to the "boot camp" in next week's show.
Saturday's edition featured Paul Gascoigne's step-daughter, Bianca, who failed to impress judges with her rendition of the Mary J Blige song I'm Going Down.
"At 25 you should be a lot better than that," commented judge Gary Barlow. "In general it was a bit of a mediocre audition."
By contrast, Belfast teenager Jade Collins turned the panel's heads, singing Beyonce's Sweet Dreams.
"We always look for a spark when someone steps on stage," commented Tulisa Contostavlos. "I saw that in you today."
The final set of auditions will be broadcast on Sunday evening.
Strictly, meanwhile, takes a three-week break as the contestants start their training. The next show will be broadcast on Friday, 5 October.