Victor Matfield’s insistence that South Africa are not the team to beat at this year’s World Rugby Classic wasn’t all that convincing even before Australia’s shock defeat to USA.

With the Wallabies, the defending champions, now facing the ignominy of playing in the Plate competition, South Africa look red hot favourites to claim their fifth Classic title.

A mouth-watering semi-final between South Africa and Australia had seemed a formality with Matfield even expressing concerns that the Wallabies’ “young and fresh” side could prove difficult to stop.

USA had other ideas, however, pulling off one of the biggest upsets in the Classic’s 25-year history after defeating Australia 15-12 on Monday.

They will now tackle the Springboks tomorrow night for a place in the final.

“I’m not sure if we’re the team to beat,” said Matfield, speaking prior to USA’s spectacular win over the Wallabies.

“If you look at the Aussies they look pretty young and fresh but, yeah, we will go for it and try and see what we can do.”

With a star-studded squad including the country’s most capped player Matfield and record points scorer Percy Montgomery, South Africa always promised to be a formidable force this year.

And they looked just that in their 12-0 triumph over France in their opening game at North Field on Monday, which saw Matfield mark his Classic debut with a try late on to seal the victory.

“It was a nice open try with no one close by so that was good,” added Matfield, who helped South Africa win the 2007 World Cup.

“At the beginning the game was pretty messy as the conditions were very hard, pretty wet, but it was a good win against a tough French side so we will take that.”

Matfield, who was renowned as the lineout king of world rugby, has been taken aback by the friendliness of the Island and spirit of the Classic.

The 37-year-old said he hoped his appearance at this year’s tournament would be his first of many.

“The guys asked me to come and play and I had been thinking about it for a while,” he said. “I will definitely be back; the whole three days so far have been unbelievable.

“There’s been a great spirit, it’s a great Island, and it’s a fantastic event.”

The Classic resumes tonight with Canada playing Italy in the Plate semi-final at 7.15pm, and Argentina taking on the Lions at 8.30pm.