Junior Wallabies back Mack Hansen says the team needs to rediscover its confidence ahead of a clash with Japan on Sunday.
The Aussies lost their first match against Wales 26-21, with handling errors proving costly in a loss that left Hansen devastated.
“I'm a little bit lost for words,” he said.
“We came in really confident to beat those blokes and to come away with a loss, it's a little bit heartbreaking.
“I think we didn't execute at all, we left at least three tries out there, so we've got to take a big look at ourselves and we've got to fire up for Japan and put some points on them now.”
Australia had plenty of opportunities, especially in the second half of their defeat, but were left to rue missed chances, and Hansen said they had no choice to but to move on quickly.
“I think we're real close to hitting our strides and if we do then I think we can beat any team and I think we will come the Japan game” he said.
“I think unfortunately this is a big kick up the arse for us so I think it'll fire us up and we'll come back from this.”
Hansen was the finisher of a spectacular Junior Wallabies try, in which James Ramm leapt up and batted the ball inside to the fullback to keep it in play.
“Been practising that cross-field a little bit but I don't think you can teach what Rammy did there in the air,” he said.
“I'll take the credit for it, but I didn't have to do much there, so give all the credit to him, to the other guy.”
Hansen said the side had to tighten up against Japan and stay switched on.
“We've got to be smarter, no dropped balls and we've just got to have a go the whole 80,” he said.
“We can't slack off at any time there otherwise you see what happens, we just get all those points put on us and it's too hard, too late to come back.
“So I think we've just got to start off firing.”
The Junior Wallabies take on Japan in their second World Rugby U20s match on Sunday, kicking off at 2pm local, 10pm AEST, broadcast on FOX SPORTS at 8am Monday.