New show Britain’s Got Talent: The Champions pulled in 5.8 million viewers on its launch episode.
Classical singer Paul Potts – the talent show’s first winner – failed to make it through to the final.
ITV said the programme was the most-watched show of the week, with a peak audience of 6.6 million.
It is a drop from the 8.1 million viewers (9.7 million peak) who tuned in for the launch of the main Britain’s Got Talent show earlier in the year.
But that featured presenter Anthony McPartlin’s return to TV following his drink-driving conviction.
A source said: “We are thrilled the launch of Britain’s Got Talent: The Champions was the most-watched show of the week and by the amazing response we have had from viewers.”
Simon Cowell’s programme features winners of versions of the talent show from around the world competing against each other.
Potts was left out of a top three of acts chosen by the audience in the first episode of the series.
A sand artist and daredevil father-and-daughter duo were the first two acts to make it through to the final.