South Korea and Denmark were involved in a remarkable battle of wits in the 2011 Double Star BWF Sudirman Cup World Mixed Team Championships at the Qingdao Sports Centre Conson Stadium on Wednesday.

At stake was top spot in Group 1D and the chance to avoid China in the quarter-finals.

After more than five hours, it was the Koreans who emerged triumphant, edging the European champions 3-2 thanks to their strength in the doubles Ko Sung Hyun-Ha Jung Eun gave them the lead with a 21-17, 21-10 win over Thomas Laybourn-Kamilla Rytter Juhl.

Former world No. 1 Peter Gade was in trouble in his match against Lee Hyun Il but showed great heart and determination to stun his younger opponent, coming back from a 19-14 deficit in the decider to win the match 15-21, 21-18, 22-20.

"I think I showed great heart and determination today. It was a real tough match but I managed to pull through to make it 1-1," said a delighted Gade.

Jung Jae Sung-Lee Yong Dae then upset world No. 1s Mathias Boe-Carsten Mogensen 25-23, 16-21, 21-14 while Tine Baun had to break out her top game to beat Sung Ji Hyun 18-21, 21-18, 21-18.

That set the stage for Ha Jung Eun-Kim Min Jung to outplay Marie R?pke-Line Kruse 21-10, 21-18.

Meanwhile, Indonesia edged Malaysia 3-2 when their mixed doubles pairing of Fran Kurniawan Teng-Pia Zebadiah Bernadet (picture) avenged their YONEX SUNRISE Malaysia Open Grand Prix Gold semi-final to Chan Peng Soon-Goh Liu Ying.

The Indonesians, who had a 4-1 winning record in head-to-heads meetings, were made to work hard in the first game where they pulled off a 23-21 win.

The second game was slightly easier as they ran away to a 21-14 victory to seal the tie and top spot in Group 1B.

Earlier, former world No. 1s Koo Kien Keat and Tan Boon Heong were unstoppable against the scratch pair of Alvent Yulianto Chandra-Mohammad Ahsan. The Indonesian camp took the risk of splitting Alvent and Ahsan from their regular partners Hendra Aprida Gunawan and Bona Septano in the hope the new partnership would beat Kien Keat-Boon Heong as they were worried Fran-Pie wouldn't be able to beat the young Malaysian mixed doubles pair.

In the end, the move proved futile as Kien Keat-Boon Heong carved out a convincing 21-15, 21-17 victory to give Malaysia a 1-0 lead.

As expected, Adriyanti Firdasari outclassed Lydia Cheah 21-8, 21-12 in the women's singles to level the tie while world No. 1 Lee Chong Wei emphatically despatched of Dionysius Hayom Rumbaka in straight games, dropping just 16 points en route to a 21-8, 21-8 victory.

Indonesia levelled when Greysia Polii-Meiliana Jauhari defeated Chin Eei Hui-Wong Pei Tty 21-18, 21-15.

Malaysian doubles coach, Rexy Mainaky said: "Chin made lots of mistakes. She tried her best but nothing seemed to work. We knew it would be hard but overall the performances were great. "It was always going to be 50-50 for Chan and Goh. The Indonesian pair had a 4-1 record coming into the match but we knew it would be close. The Indonesians attacked Chan and didn't give him time to set up the winners for Goh."

The draw for the quarter-finals will be done later tonight.