Murray won his second Masters Series title in Madrid on Sunday
British number one Andy Murray began the defence of his St Petersburg Open crown with a comprehensive 6-3 6-3 victory over Serbia's Victor Troicki.
Murray, who became the first Briton to win four tournaments in a year with his Madrid Masters triumph last week, broke Troicki twice in the opening set.
The world number four and top seed faced a break point in the second but saved it and then broke his opponent.
Murray now faces a second-round clash with Ernests Gulbis of Latvia.
It was the first time Murray, 21, had played the 22-year-old Troicki, who is ranked 53 in the world and made his first ATP final in Washington earlier this year.
"I haven't seen him play much, so I didn't really have too many tactics, but I tried to serve well and change the speed of the ball a lot," said Murray.
The Scot, who who beat Spain's Fernando Verdasco to win the St Petersburg title last season, won through in one hour and eight minutes.
Verdasco, meanwhile, beat Latvian wild card Karlis Lejnieks 6-1 6-3 in round two reach the quarter-finals, while Nikolay Davydenko pulled out with a wrist injury.
Davydenko, ranked six, advanced to the second round with a straight-sets victory over Chris Guccione but withdrew after damaging his wrist during late practice on Tuesday.
In another first round match, Kazakhstan qualifier Andrey Golubev served 19 aces to beat Olivier Rochus of Belgium 6-1 6-4.
Meanwhile junior Wimbledon champion Laura Robson suffered her second WTA Tour defeat in as many days.
The 14-year-old lost on her tour debut in the singles when she was beaten by Iveta Benesova in the first round on Tuesday in Luxembourg.
And Robson, along with Argentina's Gisela Dulko, were beaten 6-2 6-3 by Vera Dushevina and Mariya Koryttseva in the first round of the doubles.