Kläbo sprinted away from Sjur Röthe on the run.
The Norwegian men did as the Swedish sprint ladies did yesterday and took a quadruple.
Pål Golberg finished fourth.
William Poromaa came closest to challenging the Norwegian dominance, finishing fifth after being beaten by Golberg in the sprint.
Kläbo dropped several times uphill on the final freestyle but was able to catch up with Röthe and secure the silver even if he could not threaten Hegstad Krüger who danced to the front.
- It means a great deal to Simen.
There are some who believe that he should not have been allowed to start here.
There is no better way to fight back, says Norwegian national team manager Eirik Myhr Nossum to NRK.
With seven kilometers to go, Hegstad Krüger pulled away from Röthe in the heavy uphills and established his victory, the distance increasing backwards.
Shortly after the change of skis, Hegstad Krüger, Olympic distance champion in 2018, and Sjur Röthe, world champion in 2019, had broken away.
Kläbo saw the danger and stepped away from William Poromaa with whom he rode and made sure it was a Norwegian triple at the front.