Media playback is unsupported on your device Media caption Watch as Nicola Adams wins historic boxing gold at London 2012

Team GB are back to medal-winning ways after winning three more Olympic golds, including two in an hour, boosting the total to 25.

GB's Nicola Adams made history as the first-ever Olympic champion in women's boxing, in the flyweight category.

Earlier, Charlotte Dujardin won her second gold of the Games, in individual dressage at Greenwich Park.

And Jade Jones won gold in the women's under-57kg taekwondo, beating world champion Hou Yuzhuo of China.

Elsewhere, Jamaican sprinter Usain Bolt won the 200m - becoming the first man to successfully defend both 100m and 200m Olympic sprint titles.

Meanwhile, the Duchess of Cambridge and Prince Harry congratulated rowing gold medallists Andy Triggs Hodge, Kat Copeland and Sophie Hosking on a visit to Team GB House in Stratford, east London.

Media playback is unsupported on your device Media caption Dressage gold and bronze for GB

Team GB has now won 25 golds, 13 silvers and 14 bronzes, strengthening its hold on third place in the medal table.

In the boxing ring, Adams, 29, from Leeds, took on China's Ren Cancan after defeating India's five-time world champion Mary Kom 24 hours earlier.

"It's like a dream come true to me, I've just wanted this all my life, and to think I've finally done it, and I'm finally here, with all this support, it's really made my day," she said.

Dujardin, 27, won her second gold on her 10-year-old horse Valegro after a display set to patriotic music including Land Of Hope And Glory and The Great Escape. Dutch rider Adelinde Cornelissen claimed silver and Britain's Laura Bechtolsheimer won bronze.

The gold rush followed disappointment for Kerri-Anne Payne, who narrowly missed a medal in the 10k open swim.

Despite a noisy home support - her Team GB swimming team-mates and Prime Minister David Cameron were among the crowds who packed the banks of the Serpentine lake in Hyde Park - she came fourth.

Meanwhile, the South African 4x400m relay team, which includes Oscar Pistorius, has been granted a position in the final following an appeal.

Image copyright AFP Image caption Rower Sophie Hosking was congratulated by royalty

Pistorius - nicknamed "Blade Runner" because of his prosthetic legs - did not get to run in the heat as his team-mate Ofentse Mogawane was sent sprawling to the ground after a collision with a Kenyan rival. The judges have since reinstated the South Africans.

Away from the medals, London Underground cleaners have launched a 48-hour strike and are picketing stations including Stratford after not getting an Olympics bonus.

London Underground's Phil Hufton said the dispute over the cleaners was a matter between its private contractors and their staff.

He said contingencies were in place and that London Underground anticipated "no impact" on services as a result of the strike.

One 52-year-old female London Underground cleaner, who declined to be named, says her workload had significantly increased since the Olympics began.

"There's been a lot more incidents of people throwing rubbish around, like free newspapers, Olympic leaflets and maps, and lots of fast food.

"It's not just the Olympic bonus that we're unhappy about. Olympic ambassadors get free travel and the cleaners don't. We think this is unfair too."

Initial Facilities, one of the contractors, said it paid its employees the "London Living Wage" and that it was providing free Underground travel for staff during their shift throughout the Games period.

In other developments: