The first episode of the three-part thriller, about a bank employee who is coerced into facilitating a £250m internet bank theft, attracted a 21.3% share of the 9pm-10pm audience.
BBC One's 'Crimewatch', presented by Kirsty Young, pulled in 4.1m viewers and an 18.1% share.
Last night Young and the team helped the police with their hunt for a pair of gunmen who killed a manager when they opened fire in a busy office.
BBC Two's 'Amazon with Bruce Parry' came in third in the ratings battle with 3m viewers and a 13.4% share.
In the penultimate episode of the series Parry visited an illegal mine where he joined in with power hosing soil in the search for gold dust.
Five's adventure series 'Unbreakable', in which eight volunteers battle against physical and mental pressure in a bid to be declared "unbreakable", drew 800,000 viewers and a 3.2% share of the 9pm-10pm audience.
It beat Channel 4's drama 'The Shooting of Thomas Hurndall', about a young British peace activist and photographer shot by an Israeli activist, which was watched by 600,000 viewers between 9pm and 11pm, a 2.7% share. Under 100,000 viewers caught it on Channel 4+1.