The Norwegian emerged victorious from the men's freestyle mass start contest over 15 kilometres, breaking clear of rivals including the Russian Alexander Bolshunov in the closing stages.

Klæbo crossed the line 3.4sec ahead of Bolshunov, the back-to-back defending Tour de Ski champion, with Norway's Sjur Røthe third and Briton Andrew Musgrave fourth.

They were the only skiers able to challenge Klæbo's closing pace, with fifth-placed Francesco De Fabiani of Italy finishing 23.6sec behind the winner.

Klæbo now has a 45.0sec lead over compatriot Pål Golberg in the overall standings, and has 51 points - 25 more than second-placed Erik Valnes, who is also Norwegian.

The women's race, contested over 10km, ended in a sprint finish edged by Diggins.

The American, who last year became the first non-European to win the Tour de Ski, finished strongly to pip the tiring Frida Karlsson to the line.

Karlsson was 0.5sec behind in second place, Russia's Tatiana Sorina 0.8 back, and Ebba Andersson - another Swede -1.2 off the pace.

Norway's Heidi Wang completed the top five.

Diggins' win helped her reclaim the overall lead and she is now 13.0sec up on Finland's Kerttu Niskanen.

Diggins' points advantage is now 15 over Karlsson, who has 25 to the American's 40.