In the first of four 'Billy Connolly: Journey to the Edge of the World' programmes, the veteran stand-up comic took viewers on a journey along Canada's coastline, exploring communities along the sparsely populated North West Passage.
A fifth of the audience watched, while 17% tuned in to BBC One for a repeat of crime drama series 'New Tricks'.
Channel 4 screened documentary 'Britain's Conjoined Twins: Hope and Faith', who were born joined from the shoulder to the waist and underwent a 10-hour operation to be separated. The sad story drew 1.6m (including Channel 4+1 figures) and a 6.8% share.
'Natural World', following six-foot tall birds called cassowaries, managed 1.7m viewers and a 7.3% share for BBC Two at 9pm-9.50pm.
Earlier the channel almost topped 4m viewers with the hour-long semi-final of 'Masterchef' from 8pm.
'Ice Road Truckers' pulled in 1.3m viewers, giving Five a 5.4% share in the 9pm-10pm slot.