Sir David Attenborough's nature programme Planet Earth attracted nearly nine million viewers on Sunday.
A great white shark leaping to catch a seal
The first in the BBC One series, Pole to Pole, featured footage of a great white shark attacking a seal and the migration of elephants across Africa.
An average of 8.7 million viewers tuned in at 9pm but ITV1's Midsomer Murders was not far behind, with 8.4 million.
ITV1 drama Wild at Heart had 9 million viewers at 8pm, while BBC One's Just the Two of Us final got 6.1 million.
Actress Sian Reeves and singer Russell Watson beat rivals actor Mark Moraghan and pop star Natasha Hamilton.
The BBC described Planet Earth as the most ambitious factual series it has ever commissioned.
The series was made using high definition cameras and took four years to make.
Four programmes titled Mountains, Freshwater, Caves and Deserts will follow over the coming weeks and the series will continue in the autumn with another six habitats.
An elephant is filmed underwater in Botswana
The autumn shows will be accompanied by three 50 minute films called Saving Planet Earth which will look at what needs to be done to preserve the animals that have been brought to the small screen.
Sir David told the BBC's Sunday AM show that the series was the best he had worked on in more than 50 years of natural history broadcasting.
"Every series, I think, gets better, largely because of the technology," he said.
"We can do more things better than we ever did before. You get animals you never could film before, closer, better sequences.
"The aerial shots that you will see in Planet Earth simply blow the mind - at least they blow my mind."