The return of former X Factor judge Cheryl Cole has given the series a ratings boost but viewer numbers remain well down on last year.
Saturday night's ITV1 show, which saw contestants perform at the judges' houses, drew in an average 8.7 million viewers.
This was up by nearly half a million viewers on last week's episode, ITV said. The show saw a peak audience of 9.7 million.
Ratings are still below the 2011 series which pulled in an average 11.1 million viewers before the live shows last year.
ITV pointed out that the latest edition was the highest-rating show on British TV, nearly three million higher than the next nearest show.
Cheryl Cole returned to help Gary Barlow whittle down his group to three finalists
It said ITV1 was the highest-rating channel in peak-time, with an average 6.1 million viewers.
Simon Cowell's talent show is set for another ratings battle next weekend as Strictly Come Dancing returns to our screens on BBC1.
Saturday night's episode of The X Factor saw Cheryl return to the series almost two years after her departure, as a guest mentor helping pal Gary Barlow.
The Girls Aloud singer bowed out from the UK X Factor after the 2010 series to take up a short-lived place on the panel for the US version of the show.
Other guest mentors were Tinie Tempah, who teamed up with Tulisa Contostavlos, Ne-Yo who accompanied Nicole Scherzinger and Sharon Osbourne who was the sidekick to Louis Walsh.
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