After a barren opening World Cup round in Ostersund, Fak first finished third in the sprint at round two in Hochfilzen before taking his first ever victory in the pursuit.
And Fak made it two wins in two races on home snow in Pokljuka, taking victory in the 10km sprint by less than a second.
Fak, who won Olympic bronze in the 10km sprint in Vancouver in 2010, shot clear in the range to clock what was to be a winning time of 24 minutes 41.7 seconds.
Double Olympic champion Emil Hegle Svendsen missed one target in the range and it perhaps proved costly as he finished just behind Fak in second in 24:42.5.
World Cup champion Martin Fourcade appeared at one stage to be denying Fak victory after also hitting all ten targets and leading after the second shoot.
However he did not have the sprint in him to overthrow Svendsen in second let alone leader Fak as he finished third well behind both in 24:47.8.
Meanwhile of the British interest in the 10km sprint in Slovenia there was not much separating Lee-Steve Jackson in 93rd and Marcel Laponder one place behind in 94th.