ST. PETERSBURG, Russia — Defending champion Andy Murray beat Ernests Gulbis 6-4, 6-2 today to advance to the quarterfinals of the St. Petersburg Open, while eighth-seeded Marat Safin was upset in the second round.

Andrey Golubev of Kazakhstan beat Safin 6-4, 6-2 to advance to his first career quarterfinal.

Murray, fresh from winning the Madrid Masters on Sunday for his fourth title this season, won his first three games at love before saving a break point in the next game that he served.

The fourth-ranked Briton broke Gulbis in the eighth game for a 5-3 lead, but the Latvian broke back in the next game. Murray immediately broke again to take the set, and won four consecutive games in the second set to close out the match.

It was the ninth consecutive win for the U.S. Open finalist, including two victories in Britain's Davis Cup World Group playoffs against Austria in September. Murray's win-loss record this season is 50-14, making him the fifth player this year to win 50 matches.

Murray, who also won titles in Doha, Marseille and Cincinnati, plays his 10th quarterfinal this season against Janko Tipsarevic.

The Serb advanced to his fourth quarterfinal this season, beating Jeremy Chardy of France 6-4, 7-6 (3).

Safin, the 31st-ranked Russian who has twice won the tournament, had trouble on his serve, winning only 15 of 51 returned points.

The 150th-ranked Golubev, who reached the second round of the U.S. Open in September, broke Safin in the fifth game of the first set but double-faulted three times in the next game to drop serve and stay level at 3-3.

In the ninth game, Safin saved three break points with aces but was broken on the third deuce, and Golubev served for the set.

"The second break in the first set was a decisive one," Safin said. "He became confident and it was much more difficult to play against him. In fact, I didn't have many chances in the second set."

Golubev won five consecutive games for a 5-1 lead in the second set.

"I knew he would be playing his best tennis today," Safin said. "He had nothing to lose and played with no problems. No matter how I tried, it was his day today."

Golubev said his loss to David Nalbandian in the U.S. Open second round gave him experience on how to play top-ranked players.

Victor Hanescu of Romania beat Kazakh qualifier Mikhail Kukushkin 6-3, 7-6 (7).