Zenit St. Petersburg extended its winning start to the Russian Premier League season to five matches Saturday, beating Amkar Perm 2-0 to keep the top spot.
Zenit received a further boost when defending champion CSKA Moscow lost for the second game running — beaten by Rubin Kazan 2-1. The loss leaves CSKA fifth, six points behind Zenit.
In St. Petersburg, Hulk scored his fifth goal in as many league games this season with a fierce shot on 22 minutes.
That came nine minutes after the Brazilian played in midfielder Oleg Shatov to give his team the lead.
Despite Zenit's impressive start to the league season, with 17 goals scored and just two conceded, the St. Petersburg team has yet to face any of Russia's other major clubs.
Of the five teams it has played so far, none finished in the top half last season and three are newly promoted sides.
Three points behind Zenit in second place is Spartak Moscow, which held on for a 2-1 win away to FC Ufa earlier Saturday.
Spartak striker Artyom Dzyuba scored two first-half goals and now leads the scoring charts with six, but Ufa's Diego Carlos struck back on 74 minutes to ensure a tense finish.
Two weeks ago, CSKA was on a league-record 13-game winning streak dating back to last season's title-winning run, but it is now six points off the pace following its loss to Rubin.
Igor Portnyagin's goal put Rubin ahead on 17 minutes, before CSKA hit back in first-half stoppage time with a penalty by Bibras Natcho. The Israeli midfielder scored his first goal since signing for CSKA against his former team Rubin.
With the match heading for a draw, on 83 minutes Turkish winger Gokdeniz Karadeniz beat CSKA goalkeeper Igor Akinfeev to ensure Rubin's first win of the season and its first at the new Kazan Arena, a 2018 World Cup venue.
On Sunday, Dynamo Moscow can join Spartak on 12 points if it beats visitors Ural Yekaterinburg.
In Friday's only fixture, Terek Grozny defeated bottom-placed club Arsenal Tula 3-0 at home.