Samoa were outclassed 38-8 by New Zealand in their opening match last weekend, while Mate Ma'a Tonga thrashed Scotland 50-4.
The Kingdom are being talked about as a tournament dark horse after Jason Taumalolo and Andrew Fifita switched allegiance to represent their heritage.
Toa Samoa prop Herman Ese'ese said they are happy to stay under the radar.
"There's no spotlight on us. We just want to keep working hard in the dark and we'll end up turning up on the night. We're just sticking together as a tight group, as a team. We're not putting anyone else in front of us - we're just going to worry about ourselves, keep turning up for each other and hopefully we do that on Saturday night," he said.
Tonight's match comes after days of heightened tension between Samoan and Tongan fans, with both teams calling for calm after fights broke out between their supporters in South Auckland.
"There's been a lot made of it, a lot of hype around it and all you can do is just not worry about that, not let that get to our heads and just worry about our footy and hopefully we turn up on Saturday night," Ese'ese said.
"There's been a lot of talk about how good Tonga lined up and also the Kiwis and we're just going to embrace that underdogs tag and not worry about anyone but ourselves," he said.
Tonga coach Kristian Woolf says tonight's game will be a truer test of where their team is at.
He said Samoa were in the contest against New Zealand for 40 to 50 minutes and will be a whole new challenge.
"Samoa is going to come at a really high intensity. It's a real traditional rivalry clash: it's going to be tough, it's going to be physical, it's going to be an 80 minute game so we're going to have to go up a level and we're going to have to be a lot better than what we were last week, particularly in the second half."
Kristian Woolf has played down talk of his side's favouritism, saying both teams are under the same pressure to win.
"We haven't had the wins over the last couple of years so we're ranked number eleven in the world they're ranked number five. A couple of (high profile) names don't change us too much and they've got some really big inclusions if you look at guys like Josh Papalii and (Joey) BJ Leilua, who hasn't played a lot for them in the last few years, so they've got some really big inclusions at well," he said.
"It's going to be a real quality clash, it's going to be a real physical, tough clash - we're both going to have to play really good footy to get over the top of each other and that's certainly what we'll try to do," Woolf said.
Tonight's match will be the fourth time the Polynesian rivals have clashed in the past five years: with Tonga winning the inaugural Pacific Test in 2013 and Samoa prevailing in 2015 and 2016.