Beijing Olympics beach volleyball tournament wrapped up preliminary competitions on Thursday as two Chinese duos finished first in group and women's defending champions continued their winning streak.

In a men's group A match, Wu Penggen and Xu Linyin powered past Spanish pair Pablo Herrera/Raul Mesa in two straight sets 21-13, 21-15.

"From the very beginning we were ahead of them in points. We played to our usual standard," said the 1.98-meter Wu after the match.

Herrera said they could not resist the attacks of the Chinese in most of the time and the 2.02-meter Xu was the biggest headache for them. Mesa said the Chinese controlled the rhythm of match.

Wu/Xu is the only Chinese men's team to have qualified for the Beijing Olympics and is considered a medal contender. They have clinched five silver medals and two bronzes on the World Tour.

In another match in women's section, China's Zhang Xi and Xue Chen also claimed their third victory, advancing to the next round.

Zhang/Xue won over South African pair Judith Deister Augoustides/Vitalila Nel comfortably, downing the visitors in two sets (21-13, 21-9).

The Chinese women said they were in a better shape after three preliminary wins and would play in the next match without psychological burden.

"We'll go all out. We just focus on the course of the match, the result is secondary," said the 19-year-old Xue, also the youngest in the Beijing Olympics beach volleyball tournament.

Women's defending champions Misty May-Treanor and Kerri Walsh continued their dominance Thursday and finished first in women's group B.

The US pair never trailed in their third preliminary, a match with Nila Ann Hakedal and Ingrid Torlen of Norway, ending the match 2-0 (21-12, 21-15).

In women's group F, Brazil's Talita Antunes and Renata Ribeiro edged out Greek pair Vassiliki Arvaniti/Vasso Karadassiou in their last preliminary. The Brazilians also advanced as group lead.

In men's part, Clemens Doppler and Peter Gartmeyer of Austria and Jake Gibb and Sean Rosenthal of the United States also powered into the next round with three preliminary wins.

Gibb/Rosenthal had to play three matches before winning over Japanese pair Kentaro Asahi/Katsuhiro Shiratori, who had three match points in the third set but failed to clinch the victory.

Marcio Araujo/Fabio Luiz Magalhaes of Brazil and Pablo Herrera/Raul Mesa of Spain entered the next round with two victories, while in the women's part, Dalixia Grasset/Tamara Peraza of Cuba, Sara Goller/Laura Ludwig of Germany and Austria's Doris Schwaiger/Stefanie Schwaiger also advanced to the next round with two wins.

(Xinhua News Agency August 14, 2008)