BEIJING - CHINA struck first gold at the Olympic badminton on Friday after Du Jing and Yu Yang won the women's doubles title, defeating South Korea's Lee Hyojung and Lee Kyungwon who claimed silver.

Du and Yu, seeded second, overpowered the South Korean duo 21-15, 21-13 to extend China's gold medal domination of this event to four straight Olympics.

The pair dropped to the court floor after the win, before jumping into the arms of their coaches as the packed Chinese crowd roared.

The gold is the first for the Olympic badminton tournament, with China keeping its ambitions alive of taking a clean sweep of all five.

China's pair took the first game in front of the screaming, flag-waving crowd at the Beijing University of Technology gymnasium.

South Korea's fourth seeds fought back in the second, edging ahead 9-6 but China clawed their way to level at 11-11.

With the pressure mounting and the crowd upping the noise level, the South Koreans made several errors in a row, giving the Chinese the lead.

Gaining in confidence, the Chinese nudged ahead, screaming and pumping their fists with every winning point, before eventually clinching the match when the South Koreans hit wide.

China's third seeds Wei Yili and Zhang Yawen take bronze.

They defeated Japan's Miyuki Maeda and Satoko Suetsuna 21-17, 21-10, who were gunning for their country's first ever medal of any colour in badminton.

China are also guaranteed gold as well as silver in the women's singles after their last challenger, Indonesia's Maria Kristin Yulianti, was eliminated earlier Friday.

World number one Xie Xingfang will take on defending Olympic champion Zhang Ning in Saturday's final.

Zhang fought off Indonesia's unseeded Yulianti for a 21-15, 21-15 victory, the veteran of the Chinese team celebrating by throwing her racquet in the air and running to the stands to receive a bouquet of flowers from her husband.

'I finally made it and finished my task in this Olympics. I felt a lot of pressure because every match was quite difficult to win,' Zhang said.

'I'm so happy that a Chinese player will win the gold medal in these Olympics.'

Yulianti, who has been the surprise of this tournament downing players ranked much higher than her 21, battled hard but was ultimately outclassed by the 33-year-old Athens gold medallist.

'I was not ready and brave enough to give my all,' she said. 'This is my first Olympics and I thank God for the experience.'

Xie - favourite to clinch a golden double for China with boyfriend and fellow world number one Lin Dan - showed why she is the top seed in her semi-final against team-mate Lu Lan, staging a comeback to win 7-21, 21-10, 21-12.

Lu, China's 21-year-old rising star, said she couldn't keep up with Xie whose furious pace only seemed to increase as the match wore on.

'She (Xie) performed better and better throughout the match. I just couldn't keep up. She lost the first game, but she adapted a strategy to move the shuttle around the court more and sped up after that,' Lu said.

Lu raced to a one game lead with a series of deceptive drop shots against a seemingly sluggish Xie.

But Xie, playing in her first Olympics after she was left out of the team for Athens, came out firing in the second, racing to a 10-5 lead and gaining in confidence against a wilting Lu, whose earlier form deserted her.

Lu steadied in the third, taking a 4-0 lead before Xie levelled at 6-6 and then powered ahead as Lu made a glut of unforced errors. -- AFP