Samoa pushed Australia all the way in a narrow 33-26 defeat at the World Rugby Under 20 Championship in Georgia overnight.
The Baby Manu conceded the opening try in the 11th minute but right winger Tanielu Tele'a responded six minutes later to cut the deficit to one point.
The Australian captain Hamish Stewart was sent to the six minutes from halftime, with Oikoumene Paisami converting the penalty to give Samoa a 10-8 advantage at the break.
The centre missed a chance to extend Samoa's lead immediately after halftime but Alexander Pohla-Murray crossed for their second try a minute later to make it 15-8.
Back to 15 players, Australia took control of the match with three tries in twelve minutes to establish a 27-15 buffer before Pohla-Murray scored his second to close the gap the seven points.
Harrison Goddard and Ricky Pauli Ene then traded penalties in the final ten minutes with Goddard adding another on fulltime to give Australia a hard fought seven point win.
Samoa coach Mahonri Schwalger was pleased with the vast improvement from their opening round defeat.
"We learned a lot from the England game so we went back to the drawing board and we knew that Australia would be a lot harder than the English team," he said.
"We worked on our mistakes in our set-piece and defence but today we were not clinical enough, we had an opportunity but we didn't take it and it sort of cost us the game."
Australia coach Simon Cron said his team were made to work hard.
"Samoa are (an) amazing nation, a brilliant rugby playing nation. I knew it was going to be tough," he said.
"These boys are under 20 and maybe some of them didn't quite realise that.
"We made it clear during the week that this was going to be one of the toughest games that we've ever played. The Samoans were outstanding, absolutely brilliant."
Samoa's next match is against Wales on Thursday.