Tonga's 30-12 victory over England strengthened its claims as a World Cup heavyweight.
Isaiya Katoa called the result redemption after poor performances and heavy defeats to New Zealand and Samoa in last year's Pacific Championships.
"I felt like my last couple performances in the Tongan jersey was pretty poor ... so for me it was a bit of redemption," Katoa said.
"Within the four walls, we had that belief already," Katoa said of the team's confidence.
Latu Fainu left Tonga's opening game after 17 minutes; although a pectoral tear was feared, the injury now appears less severe.
The Wests Tigers half was training in Sydney on Tuesday and hopes to play Lebanon on Friday.
Katoa trained apart from his teammates while managing an ankle injury sustained in the Dolphins' finals loss to the Roosters.
"I kind of bumped it again on the weekend, very early stages in game so it's more so just to manage my load," Katoa said.
After he left the preliminary final in a moon boot, there were fears he could miss the World Cup, but the Dolphins' medical staff worked to keep him available.
"I can't thank the Dolphins medical team enough," Katoa said.
He said several staff came in on their days off during the two-week break.