China's Yi Siling has become the first gold medallist of the London Olympic Games. Yi Siling won the 10 metre air rifle shooting event. The host city, in the meanwhile, warmed up to a Michael Phelps-Ryan Lochite showdown in the pool. The US team mates square off on the opening night at the aquatic centre, which staged early drama when Phelps only narrowly scraped through his heat.2008 Olympic champion Park Tae-hwan was disqualified in the 400 freestyle. The South Korean, who won gold in over that distance four years ago, came first but had left the blocks a fraction too early. Competitions in badminton, archery, table tennis and judo also started early on a bright sunny morning in London. After Friday's opening ceremony, where Britain laid on a mesmerizing and sometimes eccentric extravaganza for the world, the host nation was hoping world champion Mark Cavendish would bring home its first gold medal in the men's cycling road race. A celebration of the country's grandeur and quirky humour, the ceremony extended into the early hours and wowed the crowd of 60,000 in the stadium and a probable billion television viewers around the globe. International Olympic Committee (IOC) president JacquesRogge told the audience: "In a sense the Olympic Games are coming home tonight. This great, sports-loving country is widely recognised as the birthplace of modern sport." On a darker note, Albanian weightlifter Hysen Pulaku became the first athlete to be ejected from the Games after testing positive for an anabolic steroid. IOC spokesman Mark Adams hoped that there will not be more. Ireland's Olympic Council said it was investigating an allegation that one of its competitors at the Games had previously bet on an opponent to win an event in which they were both competing. It did not name the athlete or the sport. More than 10,000 athletes from 204 countries will compete in 26 sports over 17 days of competition in the only city to have staged the modern Summer Games three times. The biggest event of the first day is in the pool, where Phelps defends his 400 metres individual medley title against Lochte.Phelps has 16 Olympic medals, 14 of them gold, and is bidding to become the most prolific medallist of all time by overhauling the record of 18 held by Soviet gymnast Larisa Latynina. If he wins the gold today, he will become the first man to capture three consecutive Olympic swimming titles in the same discipline. However, Lochte finished first in the US trials this year and has exuded confidence this week.Phelps, who only just scraped into the final with a desperate late lunge after easing through his heat, was relaxed and affable during his media commitments this week although still fiercely competitive. Sprint specialist Cavendish was the only member of the all-conquering British cycling team who failed to win a medal in Beijing.But this time he has the expert support of four elite competitors, including his country's first Tour de France champion, Bradley Wiggins. Six days after his triumph, Wiggins will devote his efforts to helping Cavendish win the 250 kilometer circuit to the south of London. He will be assisted by Chris Froome, second in the Tour, fellow stage winner David Millar and British champion Ian Stannard. The fact he will be a marked man adds to the pressure on Cavendish of being expected to secure his first Olympic gold and Britain's first of the Games. British excitement was stoked by Friday night's opening ceremony, a dizzying celebration of centuries of history from the Industrial Revolution to the Beatles. The audience gasped when Queen Elizabeth set aside royal reserve in a video that showed her stepping on to a helicopter with James Bond actor Daniel Craig, to be carried aloft from Buckingham Palace. A film clip showed doubles of the 86-year-old queen and Bond skydiving towards the stadium and, moments later, she made her entrance in person. In her Diamond Jubilee year, it was a moment of rare informality from a monarch revered for her devotion to duty rather than her common touch.