Johaug, who triumphed in yesterday's 10k event, finished in 25:48.0 to lead the Norwegian 1-2-3, Heidi Weng and Astrid Uhrenholdt Jacobsen finishing in second and third respectively.
Meanwhile in the men's 15k pursuit event, Norway also came out on top, Johannes Hoesflot Klaebo coming in first in a time of 35:29.7.
He was followed by compatriot Emil Iversen in second, while Iivo Niskanen of Finland finished in third.
Day 9, Sheffield
Round 1, Qualifying & Race 1 - Donington Park
Free Practice 3