The Steelers' bid for Paralympic wheelchair rugby glory has a tough road ahead after slumping to defeat at the hands of Great Britain.

Australia was beaten 58-55 in their pool B opener at Champs-de-Mars Arena on Thursday and now face a daunting task to reach the semifinals and contend for a medal.

The Steelers, who are ranked number one in the world and finished fourth in Tokyo, were neck and neck with the reigning gold medallists until GB pulled away at the start of the third quarter.

It means Australia now has little room for failure with wins against hosts France and Denmark needed to guarantee their qualification for the medal matches.

"It's not the end, we've done this before in competitions where we've lost the first game and gone on to win," said captain Chris Bond.

"It was pretty even for most of the game and then just a couple of turnovers got us down.

"We kept fighting and that's what Australians do, we stuck it right to the end and we almost turned it over.

"It was a high-quality match, and there were a couple of bounces that could have gone our way and that happens sometimes, and we were thereabouts, but we didn't do enough."

Bond contributed 12 of Australia's tries and he and Ryley Batt, who clocked a game-high 36 tries, looked in a mood to kick on after a tense first half that ended 28-27 in GB's favour.

But the Brits established a two-point gap in the opening seconds of the third quarter and turned that buffer into three in the final minute to leave Australia in a must-win scenario to get out of their pool.

"It's going to really energise the team because we have to win," Bond said.

"The nerves are gone and we just have got to go flat out and get the French.

"We've done it before, and we're going to try and relish this crowd … it's going to be bloody loud."

AAP