Wales won their first Grand Slam in 27 years this year but have suffered record defeats to New Zealand and South Africa this month. They even needed a late drop goal to beat lowly Fiji and have scored only two tries in the three games. But Thomas still believes his injury-ravaged team can salvage some pride by beating the Wallabies in Cardiff on Saturday.
"With the way things have gone this Autumn the players realise this is their last chance to put things right," said Thomas. "We wanted to play against these big teams to test ourselves but we feel we are better than this. The only way to move forward is to get a victory - that is more important to us than anything.
"We have dug in and shown improvements from each game but we know we need to cut out the errors that have been costing us so far.
"We're not looking for excuses but we've had a lot of injuries and new combinations this month and our preparation hasn't been ideal. But come Saturday, if we perform well, everything that has gone on before will be forgotten. I'm sure we can win."
The slump in form has seen Wales drop to sixth in the world rankings while Australia regained their place in the top three with an emphatic victory over Ireland in Dublin. That win ended their own miserable run of seven successive defeats while Wales have not beaten the Aussies since 1987.
Thomas added: "Australia have had a tough year but you can never write off a team like the Wallabies. They have been a top three team for the last ten years."
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.