HONG KONG SEVENS: Fiji and BlitzBoks keep clean sheets
However, the United States may be the ones to stand in their way.
South Africa and Fiji were the only teams to complete the pool stages with a perfect record of three wins.
The Fijians ended pool play with wins over Russia (36-14) and then New Zealand (50-7), with six tries in a stunning second half of that last game.
"We were clinical and accurate in what we did," said Fiji coach Gareth Baber.
"That creates pressure on our opponents and then we are quick to score."
Fiji has come to Hong Kong with a full-strength squad which they are hoping can back up and win gold at the Commonwealth Games on Australia's Gold Coast next week.
Several other nations – South Africa, New Zealand, England and Australia included – have basically sent development squads for the seventh leg of the Sevens World Series.
It means the smart money has been on the in-form islanders, who won the last World Series leg in Vancouver in March and have racked up 17 titles in total at the Hong Kong Stadium.
Their stars were on display on Saturday, too, with powerhouse Vatemo Ravouvou and the fleet-footed Eroni Sau running rampant.
But the Americans showed in winning the Las Vegas tournament at the start of March that they are now a force at the top end of rugby sevens.
There were moments that reflected that fact on Saturday as they downed Wales (47-5) and then Argentina (31-7).
Three tries to Danny Barrett against the South Americans showed a new strength inside to the US game plan, which normally relies on the scoring dash of wingers Perry Baker and Carlin Isles.
With Fiji and the United States topping their groups, the way is open for them to meet in the Cup Final Sunday at the Hong Kong Stadium.
United States coach Mike Friday said everything seemed to be falling into place for his team.
"We've started to eradicate error and introduce the more physical aspects of our game and that will put us in a good place come Sunday," said Friday.
Saturday results:
Argentina 31-14 France
United States 47-5 Wales
England 47-7 South Korea
South Africa 31-17- Scotland
Australia 14-34 Canada
Kenya 26-0 Spain
New Zealand 19-12 Samoa
Fiji 36-14 Russia
Wales 19-7 France
United States 31-17 Argentina
Scotland 61-7 South Korea
South Africa 33-15 England
Spain 17-12 Canada
Kenya – Australia
Russia – Samoa
Fiji – New Zealand
Friday results
Argentina 31-10 Wales
United States 24-24 France
England 19-22 Scotland
South Africa 45-0 South Korea
Australia 12-17 Spain
Kenya 33-10 Canada
New Zealand 36-5 Russia
Fiji 31-12 Samoa
🎥 Interview: @Blitzboks captain Dewald Human spoke to us after his side went 3 wins from 3 in Pool C at the #HK7s pic.twitter.com/SoE0CnxZ9F
— World Rugby Sevens (@WorldRugby7s) April 7, 2018