Pat Carrigan led Australia's running statistics against Samoa, gaining 163 metres from 17 runs in 43 minutes off the bench.
Tino Fa'asuamaleaui added 157 metres from 14 runs in 49 minutes as the Kangaroos beat Samoa 44-12 in their World Cup semi-final.
Australia's forwards had faced questions about their strength against Samoa and the Kiwis, who await them in next Sunday's final in Brisbane.
Samoa's pack included Junior Paulo, Spencer Leniu, Francis Manuleleua and Jermaine McEwen, but Australia's forwards lifted their performance.
The outside backs scored six of Australia's seven tries, while Jacob Preston, Keaon Koloamatangi and Cameron Murray combined for 15 tackle-breaks.
Fa'asuamaleaui said the criticism offered some motivation, but the team remained focused on the final.
"As much as it gives you a little extra motivation we can't lose sight of what the goal is," he said.
He said some had overlooked Australia's win over New Zealand in Round 1, adding, "I think a lot of people probably have disrespected us and overshadowed the fact that we did win that first game, and that's OK."
Carrigan said outside criticism did not affect the squad and could become a distraction if players let it.
Captain Isaah Yeo praised Carrigan and Murray's work off the bench, as well as the starts made by Koloamatangi and Fa'asuamaleaui.
"I thought Patty and Cam off the bench were outstanding for us, and particularly Keaon and Tino on how they started the game," Yeo said.