Top seed Andy Murray continued his good form by easing into the second round of the St Petersburg Open with a 6-3, 6-3 win over Serbia's Viktor Troicki on Wednesday.
The Briton, who won the Madrid Masters on Sunday, broke the 53rd-ranked Troicki twice in the first set and once in the second.
"I was a bit tired yesterday as I flew in here right from Madrid," the world number four told reporters.
"But today I felt just fine. I didn't have much of a plan for this match, I was just trying to put pressure on him and force him into making mistakes."
Murray, who won here last year on his debut appearance at the $1 million indoor tournament in Russia's second city, now takes on 20-year-old Latvian Ernests Gulbis.
Former world number one Marat Safin, bidding for his third St Petersburg title after winning it in 2000 and 2001, also progressed by overpowering Ukrainian Sergiy Stakhovsky 6-2, 6-4.
The big Russian, seeded eighth here, will next face Kazakh qualifier Andrey Golubev, who eliminated Olivier Rochus of Belgium 6-1, 6-4.
Third-seeded Spaniard Fernando Verdasco, soundly beaten by Murray in last year's final, was the first player to reach the quarter-finals. He overwhelmed another Latvian, the 664th-ranked Karlis Lejnieks, 6-1, 6-3.
He was joined in the last eight by unseeded German Rainer Schuettler, who dispatched Dominik Hrbaty of Slovakia 6-3, 6-3.
Second-seeded Russian Nikolay Davydenko was forced to pull out after injuring his wrist during Tuesday's first-round victory over Australian Chris Guccione.
"In one of the games when I was receiving his serve I just snapped my wrist," the world number six told a news conference.
"I was able finish the match but today I felt a lot of pain and I just can't play," said Davydenko, who has already clinched his place in next month's season-ending Masters Cup in Shanghai.