Olympics: day four in pictures

Natalie Coughlin of the United States at the start of a gold medal-winning performance in the women's 100m backstroke final Photograph: Al Bello/Getty

Serial gold medal winner Michael Phelps of the United States prepares to compete in the men's 200m freestyle final Photograph: Al Bello/Getty

The American triumphed in a new world record time of 1:42.96, before going on to the 200m butterfly semi-finals, in which he qualified again Photograph: Clive Rose/Getty

Pitcher Lai Sheng-Jung of Chinese Taipei throws a pitch against Canada during their preliminary softball game Photograph: Vladimir Rys/Getty

Players from the United States line-up before taking on Venezuela in their preliminary softball game Photograph: Vladimir Rys/Getty

Spain's Jorge Pina, left, and Italy's Diego Occhiuzzi both celebrate alleged hits during their men's individual sabre match Photograph: Philippe Desmazes/AFP

The USA's Raj Bhavsar competes on the parallel bars during the men's team final of the artistic gymnastics event Photograph: Kazuhiri Nogi/AFP

TV screens showing Artyom Shaloyan of Germany competing in the weightlifting event Photograph: Ezra Shaw/Getty

Members of the Chinese team hold hands on the podium after winning the men's team artistic gymnastics gold medal Photograph: Hans Deryk/Reuters

Armen Nazarian (red) of Bulgaria tussles with David Bedinadze (blue) of Georgia in the men's Greco-Roman 60 kg qualification wrestling event Photograph: Stu Forster/Getty

Venus Williams of the USA serves to Iveta Benesova of the Czech Republic during their women's singles second round clash Photograph: Toby Melville/Reuters

A crowd of volunteers watch the field hockey competition between Argentina and Great Britain Photograph: Rick Rycroft/AP

Lee Baeyoung of South Korea falls as he fails to lift 186kg on his third attempt during the men's 69kg Group A clean and jerk weightlifting Photograph: Yves Herman/Reuters

Vavrinec Hradilek of the Czech Republic competes in the Men's single K1 Kayak semi-final Photograph: Adrian Dennis/AFP

Jakob Johann Sveinsson of Iceland pulls off his swimming cap after competing in his men's 200 metres breaststroke heat Photograph: Wolfgang Rattay/Reuters

Canada's Melissa Tancredi scores with a diving header in their women's first round group E football match against Sweden Photograph: Frederic J. Brown /AFP