Linn Svahn and Erik Valnes topped penultimate stage races at the Tour de Ski while Jessica Diggins and Harald Østberg Amundsen retained the overall lead into Sunday’s finale in Italy. Svahn beat Swedish team-mate Frida Karlsson on the home stretch of the 15 kilometres classic style mass start race in snowy Val di Fiemme, with Katharina Hennig of Germany completing Saturday’s podium in third. “It was a crazy race again. I felt strong the whole way but actually I think Frida was the strongest today, she did all the work,” Svahn said. Diggins trailed by 5.7 seconds in eighth place and is one stag…