Alexander Kerzhakov scored a hat-trick to help Zenit to a 6-1 win which kept them four points clear of second-placed Rubin Kazan with two games in hand.

Kerzhakov started the rout in the 25th minute and a Danny penalty and a Danko Lazovic effort in the space of three minutes just after the half-hour mark put the hosts in total control.

Dmitri Kirichenko pulled a goal back for Saturn a minute before the break, but Kerzhakov got his second a minute after the restart and completed his hat-trick eight minutes later.

Substitute Alessandro Rosina made it six seven minutes from time.

Rubin were 1-0 winners at home to Alania Vladikavkaz thanks to Salvatore Bocchetti's 39th-minute goal.