The final part of the four-part drama, starring new Bond girl Gemma Arterton as Tess, attracted 5.6m viewers and a 22.1% share of the 9pm to 10pm audience.
It gained 600,000 viewers from the third episode shown last Sunday, but was 100,000 down on its debut.
'Tess' was beaten by ITV1's airing of 'Harry Potter and the Goblet of Fire', the fourth film in JK Rowling's wizard series starring Daniel Radcliffe, which pulled in 7.2m viewers and a 28.4% share of the 7.15pm to 10pm audience.
The second part of 'James May's Big Ideas', which saw the 'Top Gear' presenter exploring the world of robotics, drew 2.4m viewers to BBC Two and a 9.3% share of the 9pm to 10pm audience.
'The Secret Policeman's Ball 2008', featuring comedy performances by Russell Brand, Graham Norton and Eddy Izzard at the Albert Hall, netted 1.8m viewers for Channel 4 and a 7.7% share of the 9pm to 10.30pm audience. Including Channel 4+1 figures it reached 1.9m viewers.
'Hart's War', starring Colin Farrell and Bruce Willis, pulled in 1m viewers and a 5.4% share of the 9pm to 11.30pm audience for Five.
Earlier in the evening, ITV1's 'X Factor' attracted 9.5m viewers (42.5%), who tuned in to see the final 12 chosen for the first live show next week.
BBC One's 'Strictly Come Dancing' results show pulled in 8.4m viewers and a 31.4% share of the 8.15pm to 9pm audience.
On Saturday night 'X Factor' narrowly beat 'Strictly Come Dancing' with 9.8m viewers and a 40.3% share of the 7.45pm to 9.15pm audience.
'Strictly Come Dancing' attracted 9.2m viewers, a 39.8% share of the 6.45pm to 8pm audience, as people tuned in to see the male contestants dance for the second time this series.