Great Britain opened their Paralympic wheelchair rugby campaign with defeat against reigning champions the United States today - but captain Steve Brown was far from disconsolate.

Brown's team are widely viewed as strong medal contenders, and they led the reigning Paralympic champions 13-11 after a fierce opening quarter at the Basketball Arena.

Despite a 16-goal display from star performer Aaron Phipps and an 11-goal contribution by the workaholic David Anthony, though, Britain lost their Pool A opener 56-44.

But France are next up tomorrow night, followed by Japan on Friday, with successive victories certain to secure semi-final status.

A capacity 10,000 crowd, including Mayor of London Boris Johnson, ensured an electric atmosphere for the eagerly-awaited tournament launch of a sport originally known as murderball due to the ferocious collisions between players.

"The States are number one in the world, so it was never going to be easy. We had the bounce of the ball sometimes, and other times it went against us," Brown said.

"But I am so proud to be captain of a team that gave 100% right until the end.

"That crowd was something else. You have to draw from the crowd and find that extra percentage with your performance, but it is also important to remember they are outside the court and you have to focus on what happens inside the four lines.

"You really go hell for leather, and the crashes are all part of the game.

"It's tactical. You want to stop the player moving, you want to knock them out of their chairs so you've got a numerical advantage.

"The game works to involve the hits. It is not just a case of bumper cars with the ball.

"In so many areas we match up with America - our strength, speed and agility. Player for player there is very little difference.

"They are number one in the world and they are very well-oiled machine. We had tactics and ideas of ways we wanted to perform, and we did our best with that.

"We have a game-plan for every opposition, and when we take on France tomorrow we will play differently from how we played today.

"We will look at what went right and what went wrong, but it is game by game, plan by plan. We are not going to take everything back to the drawing board after four years because of one defeat."

Brown scored the tournament's first goal, and America were kept in check until the early part of a second quarter that saw them outscore their opponents by seven goals.

The defending champions then eased through the gears, with the brilliant 14-goal Chuck Aoki in commanding form, although he was ultimately outshone by Phipps.

Southampton-based Phipps was the only player involved today with the sport's highest value classification of 3.5, and he certainly delivered.

"I was so nervous in the tunnel before the game," he said. "I played quite well when I was on court, but the United States are so clinical with the ball.

"France doesn't have the experience that America has, but this is not an easy group, and the other one is just as tough. Potentially, six of the teams here could medal.

"I think we match up well against France. I am confident we will beat them, and I'm definitely confident we will still medal."

Kylie Grimes, the only female player in Britain's ranks - and one of only two in the tournament - added: "We came out really strong.

"America were a bit shaky, which I was pleased about, but they are a very experienced, well-drilled team.

"I get asked all the time about being the only woman in the team, but that's fine. They don't treat me any differently and they hit me just as hard, and that's the way it should be."

The United States now go on to play Japan tomorrow night, and coach James Gumbert was relieved to have got through a demanding first fixture.

"The fans were phenomenal, and Britain came out and threw everything in the tool-bag at us. We had to go back, find another tool-bag and get some old tools out," he said.

"They are a quality team - they played like champions - and we knew we would have to weather some storms.

"We felt like the underdog today, and it's not often we feel that way."