KUMAMOTO, Japan, Nov. 9 (Xinhua) -- European champion Italy and United States marched on towards Olympic qualifications as both teams collected their sixth straight wins at the women's volleyball World Cup on Friday.

The Italians brushed aside Poland 25-15, 25-15 and 25-18 in Sapporo. With Kenya and Peru next up for Massimo Barbolini's brilliant blues at Hokkaido Prefectural Sports Center, Italy has a wonderful opportunity of heading for the Nagoya climax at 8-0 and looking good for Beijing Games.

"I am really happy for this result of my players and for our ranking, too, because for us it was very important to win against Poland," said Barbolini. "I think we played the best match until now in this competition. We have played a very good match against a team that is at the same level as Cuba and the United States."

Francesca Piccinini led Italy with 19 points and Taismary Aguero added 15.

Marco Bonitta, former coach of Italy, was upset after his side's fourth defeat in six matches.

"We played a very bad game, the worst we have played in this competition. We played without a strong mentality," said Bonitta. " Italy played a very good game, their defense was good and our attacks were always being dug up."

The United States overcame a surprising slump in the second set to beat Dominican Republic 25-16, 20-25, 25-16 and 25-18 to remain untouched.

The Americans started well in its first match at the Kumamoto Prefectural Gymnasium, taking the first set 25-16 without much difficulties.

However, Sidarka Nunez and Bethania De La Cruz came out big in the second set to lift the Dominicans to a 4-0 run which pushed them up at 18-15, a gap the United States could never close.

"We were not very focused at the start, but well enough to win the first set," said United States captain Robyn Ah Mow-Santos, who replaced starting setter Lindsey Berg from the beginning of the third set. "But we lost focus in the second set, I don't know why. It's a good thing that we came back to win the next two sets."

With the help of Ah Mow-Santos, the Americans found back their effective attack again in the third set, where they ran off four straight points to enter the second TTO at 16-10 up and never looked back.

In the fourth set, the United States raced to a 12-6 cushion and went on to seal the victory in just over one and half hours.

Logan Tom led the United States with 18 points with Tayyiba Haneef-Park and Danielle Scott-Arruda adding 13 and 11 respectively.

Despite its fifth loss in six tries, Dominican Republic got some consolation from remarkable performances of the 20-year-old Nunez and 18-year-old De La Cruz, who scored 18 and 17 points respectively.

It seems the Cuban women have been addicted to playing in full sets.

Going into the tie break for the fourth time in six matches, Cuba wore down South Korea 25-20, 17-25, 19-25, 25-21 and 25-10.

Having collected four wins against two losses, the Cuban team is still in contention for a top three finish in the 12-team round-robin tournament and a ticket Beijing.

"Yes, we have played tie breaks quite a few times in the last matches, but we will be very happy if we can always win, like we did today," said Cuba head coach Antonio Perdomo. "However, it will be very difficult for the players to play many full sets matches in a long tournament like the World Cup."

"The South Korean team did not play very fast in the beginning of the match, but they were getting faster and faster, which made it very difficult for us," Perdomo added. "It was a very difficult game and we are satisfied with our overall performance."

Yumilka Ruiz and Nancy Carrillo were the heroines of Cuba in the hotly contested tie break. After a kill of Han Yoo-mi made it10-9 in favor of South Korea, Ruiz drove consecutive fine spikes to help Cuba overtake the lead at 11-10. Then Carrillo had two aces in a row before forcing successive South Korean errors with another pair of storming services to seal the victory for Cuba.

Ruiz finished with 18 points for Cuba and Carrillo added 17.

Kim Yeon-koung had game-high 21 points for South Korea, who slipped to a 2-4 win-loss record.

In Friday's other action, Brazil swept Thailand 25-12, 25-13 and 25-20, Serbia outclassed African champion Kenya 25-15, 25-16, 25-10 and Japan beat Peru 25-18, 25-13, 22-25 and 25-19.

Brazil, Serbia were both on a 5-1 win-loss record while Kenya and Thailand have yet to find a win.