Artem Dzyuba hits his half century in the win over Krasnodar
The brace in Saturday's game was Dzyuba's 50th and 51st goals for Zenit.
Yaroslav Rakitsky had given Zenit a 2-1 lead inbetween the Dzyuba strikes with another trademark freekick.
Zenit are now 8 points clear at the top of the Russian Premier Liga with six games remaining.
Artem Dzyuba joined Zenit on 1 July 2015 and has played a total of 138 matches and scored 51 goals. These are made up of 35 in the league, 2 in the Russian Cup and 13 in European competition.
He is the fifteenth in the list of top scorers in the club's history. Alexander Kerzhakov remains in first place with 163 goals.