Mansell mastered challenging weather conditions on Friday to take the 36 hole lead with a 68 at the Old Course, St Andrews, and shone again on a bright but breezy day half an hour up the road, posting six birdies and one bogey to reach 15 under.
Ten-time DP World Tour winner Alex Noren spent much of the round at the summit alongside Mansell - who has recorded three top-five finishes this season - but sits four back after his three-under 69 at the Old Course.
The Swedish Ryder Cup star shares second spot with Englishman Daniel Gavins and New Zealand's Ryan Fox, who both produced strong finishes to their rounds at Kingsbarns Golf Links.
Antoine Rozner of France and Dane Niklas Nørgaard Møller are then on ten under par, with England’s Callum Shinkwin a shot further back.
Rasmus Højgaard is at eight under par after a 67 at the Old Course, as he was paired with twin brother Nicolai for the first time on the DP World Tour, alongside Finn Tapio Pulkkkanen and South African Christiaan Burke.
Burke also leads the team championship alongside partner Bruce Mitchell at the unique event which brings together some of the world’s best golfers with amateurs including celebrities from the worlds of sport, music and film, playing in an individual and team competition across three world-class links courses.