Tuqiri made an impressive return to international rugby on Saturday with a man-of-the-match performance in his side's 49-0 victory over Fiji.
He had been controversially rested during the Wallabies' recent Two-Test series with Wales after selectors sent him into temporary exile in an attempt to regain his blistering speed.
The flying winger managed only one try for the entire 2007 Super 14 competition, leaving Wallaby selectors concerned ahead of their World Cup campaign which features a clash with Wales at Millennium Stadium on September 15.
"Being a World Cup year there will be bigger games later in the year, but beating South Africa is a huge fish to fry for us," Tuqiri said.
"Next week will be the big telling point of where we are really at; we will see what sort of side they pick, what sort of side we pick, and I'm confident of the guys playing around me."
South Africa showed glimpses of what they are capable of with consecutive defeats of an under-strength England, 58-10 and 55-22, and will look to continue their momentum in the Tri Nations opener on Saturday.
But a confident Tuqiri claims the Wallabies have the ability to stop the Springboks on their own turf.
"They are a little more scary to play over there (South Africa), but I have the confidence in the guys around me," Tuqiri said.
"I feel we have improved since this time last year, especially our forwards, so they will be ready for them.
"You want to win games all the time you can, and I want to win over there. If we can do that it will be a massive boost for us going into the World Cup.
"It will give us a lot of confidence for when we face them in the World Cup, so this is a crucial game."