Portuguese forward Eder's goal in the 87th minute of the match was enough to give Lokomotiv a seven-point lead in the standings, meaning they cannot be caught by rival clubs.
Eder came off the bench in the 80th minute and buried a cross by Vladislav Ignatyev to earn his team the title.
Russia is hosting the World Cup from June 14 to July 15 in 11 cities including Moscow, St Petersburg and Sochi.
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(Reporting by Gabrielle Tétrault-Farber; Editing by Clare Fallon)
