The two shows were neck and neck on 7.3 million viewers when overnight audience figures were issued last week, but "consolidated" figures - which include catch-up viewing - show the BBC1 hit was half a million ahead.
It drew 10.15 million viewers for its December 25 special, while ITV1's Downton had 9.60 million (including viewers of the ITV+1 channel).
In 2011 Downton was the big winner based on consolidated figures, which meant that, after time-shift viewing was included, it was the biggest Christmas Day show.
However, its seasonal edition screened last week - in which Dan Stevens' character Matthew Crawley was killed off - proved to be the sixth most popular show of the day.
EastEnders retained its position as the most popular show of the day, according to the new figures, while Midwife was second.
:: The Christmas Day top 10 based on consolidated figures is as follows (with the original overnight position in brackets):
1 (1) EastEnders 11.20 million viewers
2 (6=) Call The Midwife 10.15
3 (4) The Royle Family 9.87
4 (5) Doctor Who 9.85
5 (2) Coronation Street 9.65
6 (6=) Downton Abbey 9.60
7 (3) Strictly Come Dancing 9.12
8 (9) Emmerdale 6.81
9 (8) The Queen 6.47
10 (10) BBC News 6.14