The father-son tandem of Petter and Oliver Solberg beat the surprisingly competitive American team of Colton Herta and Jimmie Johnson on the the frozen Baltic Sea to win the Race of Champions (ROC) Nations Cup. Team Norway was led Saturday by 47-year-old Petter Solberg, the 2003 World Rally Champion and two-time World Rallycross Champion. His son, Oliver, is a 20-year-old rising rallying driver. The knockout-round style event was held on the snow- and ice-covered course in Pite Havsbad, Sweden, 60 miles south of the Arctic Circle. Herta was a last-minute replacement for Travis Pastrana, who broke his back and hip in a BASE jumping accident late last month. The 21-year-old IndyCar star replaced Pastrana and left for Sweden after leading his team to a class victory last Sunday in the Rolex 24 at Daytona. Johnson, the seven-time NASCAR champion who is headed into a full IndyCar season this month, returned …