Without much competition in the schedules, the launch night episode of the reality show collected an audience of 3.5 million for Channel 5 (a 15.8% share).
The Brian Dowling-hosted show peaked with a crowd of 4.4 million as famous faces such as Frankie Dettori and Rylan Clark entered the house.
Channel 5 beat all the channels in the 9pm-11pm timeslot, apart from BBC One, who drew 4.49 million to DIY SOS at 9pm.
Emma Willis's Big Brother spinoff series Bit on the Side collected 1.15 million viewers at 11pm for the channel.
Channel 4 had 1.14 million viewers for Millionaire Playboys at 9pm, while numbers fell to 360k at 10pm for The 15 Stone Babies.
BBC Two had a healthy 1.2 million viewers at 9pm when it aired the movie Mrs Brown.
ITV had 2.8 million viewers for Trouble Ahead at 9pm.