Sun Longjiang, the speed skater who was questioned over his qualification to the 12th National Winter Games of China due to a reported doping offence, claimed the gold medal in the 5,000-meter race here on Thursday. The 19-year-old defending men\'s all-round champion clocked the fastest time of six minutes and 44.45 seconds. Daxinganling team\'s Li Bailin grabbed the silver in 6:47.95, just 0.08 seconds ahead of Zhang Haiming of the PLA, who rounded out the podium. An anonymous source told the Chinese version of Yahoo! website late on Wednesday that Sun was tested positive for clenbuterol in 2011 and thus should not be eligible for competing at the Jan. 3-13 Winter Games. But China\'s anti-doping center explained that Sun was exempted from punishment as his positive test resulted from eating contaminated food and gave him the green-light to represent Jilin at the quadrennial event. In Thursday\'s men\'s 500m sprint, Sun\'s teammate Zhang Hongliang took the title with a time of 36.88 seconds, beating Sun to the second place in 36.95 and Changchun\'s Cheng Yue was third at 37.09. Jilin\'s Dong Feifei came out the women\'s 500m winner in 39.90 seconds, while Wang Fei, who represents the PLA, won the women\'s 3,000m with a time of 4 minutes and 19.96 seconds.