HAMAMATSU, Japan, Nov. 4 (Xinhua) -- The United States tamed Poland in four sets here on Sunday to remain unbeaten in the 2007 women's volleyball World Cup ongoing in Japan.

With the well-deserved 25-25-21, 12-25, 27-25 and 25-17 victory, the Americans improved their win-loss record to 3-0, dropping the Polish women to 1-2.

"Poland is a great team, they serve very tough and have great defense, as well as two great outside hitters," said U.S. head coach Lang Ping. "We played well as a team and concentrated well."

The Chinese coach believed good communication and teamwork was the key to her side's big wins in the last two days.

"We didn't get together for a long time, but the players know we have to communicate well and do better as a team, so I think we did a pretty good job in the last two matches. I'm happy for the players," she added.

The United States enjoyed a balanced offense with Tayyiba Haneef-park scoring 13 points to lead five Americans in double digits.

Poland coach Marco Bonitta attributed the loss of his side to its unforced errors.

"The difference was we made more mistakes, I think 26 to only 12 for the U.S," said Bonitta. "Mental weakness is a problem for us and we must try to correct this, but I believe in our potential to win."

After splitting the first two sets between themselves, the United States and Poland fought hardly in the third, where neither team could pull away. It was the European wild card holder who clinched a set point first at 24-23 through a serving error of Logan Tom, but the United States beat off two set points for an advantage at 26-25 before Ogonna Nnamani drove a ball out of bounds to clinch the set at 27-25.

In the fourth set, Poland built up a lead at 10-8 and held it to 14-12, only to see the Americans surge away with a 9-1 run for an cushion at 21-15.

In Tokyo, European runner-up Serbia was seriously tested before beating the host Japan 25-20, 25-20, 18-25 and 26-24.