Japan's Kohei Uchimura has vowed to "go on the rampage" and break the Chinese stranglehold on men's Olympic gymnastics when the Games competition gets underway on Saturday. Four years ago, then hosts China dominated, winning seven of the eight men's titles, including the team gold and beating 2004 winners Japan by more than seven points. China's now-retired Yang Wei also won the individual men's all-around gold, leaving Uchimura with silver. Since Beijing, Uchimura has been undefeated -- winning three consecutive world all-around titles -- and now the Olympic gold is seen as his to lose. "I want to go on the rampage and deliver a really elegant performance on the London stage," he said this week. "I don't feel any pressure and want to repay double the expectations people have of me. I am 120 percent confident of winning a medal."The 23-year-old took gold at the World Championships last year in Tokyo ahead of Germany's Philipp Boy and fellow Japanese Koji Yamamuro, who will also be among his challengers in London. Despite Uchimura's personal success, Japan failed to take the team title from China at the 2010 and 2011 worlds, while the United States finished just 0.010 points behind the Japanese in Tokyo. "I am only thinking about the gold medal in the team event," said Uchimura, who will also be targeting individual gold on the floor and the high bar. "Since the Beijing Olympics, we have only managed silver. I don't want to feel the same disappointment any more." London holds fond memories for Uchimura, as it was the venue for his first world title in 2009. The Japanese have not looked enormously convincing in training, however, with Uchimura notably falling twice from the high bar during podium practice on Wednesday. China possess a formidable team, although they have been weakened by the withdrawal of 2004 Olympic pommel horse champion Teng Haibin due to an arm injury. His place has been taken by Guo Weiyang, who lines up alongside Chen Yibing, Feng Zhe, Zhang Chenglong and Zou Kai. The only title to elude the Chinese men in Beijing was the vault, with Poland's Leszek Blanik winning ahead of France's Thomas Bouhail. It is another Asian, South Korea's world champion Yang Hak-Seon, who is among the favourites on that apparatus in London. Hosts Great Britain have one of their best gold medal chances on the pommel horse, with Louis Smith bidding to better his bronze in Beijing. At 26, Jonathan Horton, twice a medallist in Beijing, is the only gymnast aged over 20 in a youthful United States men's team. In the women's competition, China took two of the six golds on offer in Beijing -- defeating the United States for the team crown, with He Kexin winning on the uneven bars. But the USA are the reigning world champions ahead of Russia and China and are widely seen as the favourites for gold in London. Reigning world all-around champion Jordyn Wieber of the United States could be challenged in her bid to claim the Olympic gold by Russians Aliya Mustafina and Viktoria Komova. Britain's 2009 world floor champion Beth Tweddle will be bidding for gold on that apparatus and is also carrying home hopes on the uneven bars, on which she is a two-time world champion. The gymnastics tournament opens with men's qualifying on Saturday, followed by women's qualifying on Sunday.