Nearly four million people stayed up to watch the opening ceremony of the Rio 2016 Olympics - less than a fifth of the number that tuned in for the curtain-raiser of London 2012.
Provisional ratings for the ceremony, which lasted well into the early hours of Saturday morning, suggest an average of 3.8 million viewers watched BBC1´s coverage.
The equivalent figure for the 2012 opening ceremony was 22.4 million.
Audiences were always likely to be smaller on this occasion, given the four-hour time difference between the UK and Brazil.
This year's ceremony did not begin until midnight in Britain, compared with a 9pm kick-off in 2012.
The official ratings for the 2016 ceremony are likely to go up significantly once viewers watching on catch-up are included.
A final figure will be published next week.
Catch-up audiences boosted ratings for the 2012 ceremony from 22.4 million to 24.2 million, making it the second most-watched TV broadcast of the decade so far.
The most-watched is the 2012 Olympics closing ceremony, which attracted a total audience of 24.5 million.