Packed crowds greeted the first day of athletics at the Paralympics but the jubilant mood was overshadowed by a mix-up that saw the wrong athlete awarded a gold.
There was controversy, too, at the Velodrome, where the British favourite in the men's C4/5 1km time-trial angrily protested a decision not to allow him to restart after slipping at the start.
The day had started off well, with nearly 80,000 people packed into the Olympic Stadium in east London roaring T54 wheelchair racers around the track in the women's 5,000m heats to the astonishment of athletes.
There were few spare seats for the evening session, which notably saw Ireland's Jason Smyth -- who trains with US sprint star Tyson Gay -- lower the men's T13 100m world record to 10.54secs in qualifying.
The woman who set the first world record at the venue during a test event back in May, British wheelchair racer Hannah Cockcroft, also gave home fans reason to cheer by clinching the women's T34 100m crown.
Athletes paid tribute to the support, which London 2012 chief Sebastian Coe said was a "very powerful and eloquent statement about the status of the sport", showing they had recaptured the atmosphere of the Olympics earlier this month.
Denmark's Jackie Christiansen, who won gold in the men's F42/44 shot with a throw of 18.16m, said: "It was really exciting out there. It was surely the biggest crowd I've seen in my lifetime.
"And the crowd were great. They were with us all the way."
There was an inspirational performance in the pool, with former US Navy lieutenant Bradley Snyder winning gold in the men's S11 100m freestyle, nearly a year after he was blinded by an improvised explosive device in Afghanistan.
He said it showed what was possible for anyone affected by life-changing injuries.
"Hopefully, my presence here, representing the flag in a different manner, can provide some inspiration to those guys so they can get out," he told reporters.
"It doesn't have to be sport but just get out of bed, get back into life and get through the barriers that have been presented to them."
In the US team, more than 20 of the 227 athletes are veterans.
Former British Royal Air Force weapons specialist Jon-Allen Butterworth, who lost an arm in a rocket attack in Iraq in 2007, earlier won silver in the men's C4/5 1km time-trial.
There was no medal, though, for Britain's Derek Derenalagi, who in 2007 was officially pronounced dead and put in a body bag after being blown up by a landmine in Afghanistan, until medics found a pulse.
He failed to make the final of the men's F57/58 discus but was given a hero's welcome by the crowd.
Martine Wright, who lost both legs during the Islamist suicide bombings on London's public transport network on July 7, 2005, also made an emotional debut in the Paralympics, as Britain took their Games bow in sitting volleyball.
Seven years ago, Wright was on her way to work and reading about London's successful bid to host the Olympics and Paralympics announced the day before when the bombs went off, has become one of the inspirational stories of the Games.
"It was absolutely amazing," she told AFP after the match. "I've been on quite a journey the last few years.
"To be able to finally get on court in front of my friends and family that have supported me and been so important to me over the last few years was an absolute dream come true -- and a dream that I never actually would have had before July 7."
The mood was soured, however, after organisers admitted that "inaccurate results data" meant the first field event gold medallist -- Mariia Pomazan of Ukraine -- was wrongly awarded the F35/36 discus title.
The result was amended and saw Pomazan relegated to silver, swapping places with China's Wu Qing, while Wu's compatriot Bao Jiongyu was relegated to fourth. Her bronze was taken by Australia's Katherine Proudfoot.
In the Velodrome, Britain's Jody Cundy, the favourite in the C4/5 1km time-trial, was left angry and distraught after slipping out of the starting gate and being denied a restart by officials.
He was led away from the track shouting and swearing after throwing a water bottle, as British team officials lodged a protest. But world governing body the International Cycling Union (UCI) held firm, blaming the slip on "rider error".
Britain's David Weir (C) competes in the men's 5,000m - T54 round 1 athletics track event during the London 2012 Paralympic Games at the Olympic Stadium in London on August 31. Packed crowds greeted the first day of athletics at the Paralympics but the jubilant mood was overshadowed by a mix-up that saw the wrong athlete awarded a gold.
US swimmer Bradley Snyder poses with his gold medal after winning the men's 100m freestyle - S11 final swimming event at the London 2012 Paralympic Games at the Olympic Park's Aquatics Centre in east London on August 31.
Discus athletes Ukraine's Mariia Pomazan (C) poses with China's Wu Qing (L) and China's Bao Jiongyu (R) during the London 2012 Paralympic Games. Organisers admitted that the first field event gold medallist -- Pomazan -- was wrongly awarded the F35/36 discus title.
Great Britain's Martine Wright (2nd R) celebrates a point with team-mate Victoria Widdup (L) during their women's sitting volleyball match against Ukraine during the London 2012 Paralympic Games at the ExCel Centre in east London.
Britain's Jody Cundy (L) talks with para-cycling coach Chris Furber (R) after being denied a restart in the men's individual C4-5 1km time trial cycling event during the London 2012 Paralympic Games at the Olympic Park's Veldrome in east London on August 31, 2012.