The Springboks have recovered solidly from losing 34-32 to Japan in Brighton in their opening match, amassing 80 points and scoring nine tries as they claimed emphatic victories over Samoa and Scotland.
And a win is all they need at the Olympic Stadium today to guarantee topping Pool B, confirming a last-eight appointment with Australia or Wales.
“There are so many examples of comebacks throughout the world, of things that people said could never happen,” South Africa coach Heyneke Meyer said.
“They said the mile would never be run in under four minutes, and now everybody’s running under four minutes.
“I am a very positive person. I believe that anything is possible, and I have been in situations where I’ve lost every single game, come back and won trophies. But we don’t look past this game. I mean it.”
Meyer has made two injury-enforced changes from the team that defeated Scotland, with wing Lwazi Mvovo replacing JP Pietersen and prop Frans Malherbe handed a start instead of Jannie du Plessis.
“We always have dreams and goals of achieving success at this World Cup,” Springboks wing Bryan Habana said.
“Japan was 100 times more disappointing for us than it was for anyone outside this group. The response this past two weeks has been good, but we still believe we’re not quite there yet.
“We believe if we are going to get to the next stage, we are going to have to improve. USA may not be ranked in the top ten, but we’ve already seen that their physicality and intensity and their approach doesn’t make it easy to play against them.”
USA head coach Mike Tolkin retains just three players – skipper Manu Samoa, hooker Phil Thiel and full-back Blaine Scully – who were on starting duty last time out against Scotland, with one eye also on Sunday’s appointment with Japan in Gloucester.
“It comes to a point in this tournament with a four-day rest where you have to use the whole squad,” Tolkin said.
“Every team that has been in this situation has had to do the same thing.
“The morale is good, the work ethic is very good.
“We are just disappointed we didn’t get those wins [against Samoa and Scotland].
“We knew each World Cup game is a challenge, but we also felt that we could win.
“For a lot of players who haven’t played full-time it’s difficult to come in after three months and have a high-pressure game after high-pressure game.”