Edwards explained that the narrow defeat to the Springboks by one point meant Wales will now need to win all their remaining pool games to ensure a quarter final place.
But he said the team can take plenty of positives from the encounter with South Africa as they prepare for the next challenge.
Looking back at the first game he said: "We more than competed in the scrums at the weekend against one of the most vaunted scrums in the world. We also have to at least match the southern hemisphere teams at the breakdown in defence and attack and at the weekend I thought we achieved that."
Edwards said the Samoan team will pose a similar threat to South Africa in the way they will attack Wales.
He said: "They are big. Powerful men the same as the South Africans. In attack they like to offload the ball and they also like to go for the intercept. It will be important to keep up our tackle percentages and create momentum to go forward."
He said Wales will not mind going into the game as favourites if pundits want to award them with that tag.
"If someone wants to put that tag on us that's fine. We will just want to deliver on the day and get the job done," added Edwards