Sweden and holders the United States will meet in the Women's World Cup last 16 while South Africa stunned Italy for a first win ever at the tournament on Wednesday and a place in the knockout stage.

The Americans came into the tournament in Australia and New Zealand as favourites to win an unprecedented third World Cup in a row.

But they have looked nothing like the team that has for so long dominated women's international football and only scraped out of the group phase with a shaky 0-0 draw against debutants Portugal on Tuesday.

Sweden will be a whole different proposition on Sunday in Melbourne, having won all three of their group games and scoring nine goals in the process.

They confirmed top spot in Group G with a 2-0 win over an Argentina side on Wednesday that finished bottom with a solitary point and are on their way home.

A Rebecka Blomqvist header and an Elin Rubensson penalty did the damage for Sweden, who are ranked three in the world to the USA's one.

South Africa finished second in the group and will play the 2019 runners-up the Netherlands for a place in the last eight.

It was a historic evening's work for the African champions, their stunning 3-2 win over Italy a first World Cup win and taking them into the knockouts for the first time too.

Italy, who had only needed a draw to go through, are instead going home.

Captain Thembi Kgatlana scored a dramatic winner in the 92nd minute for South Africa.

"They fought like warriors. They fought like the heroines that we know that they are," said coach Desiree Ellis.

"They've made history – not just getting our first win but a place in the round of 16.

"And that is freaking amazing."

Later Wednesday, Jamaica will also look to reach the knockouts for the first time when they face Brazil knowing they only need a point.

Brazil must win to be sure of reaching the last 16.

Also in Group F, France only need a point against already eliminated Panama.

CAICEDO '100 PERCENT'

Group action concludes on Thursday with Colombia in pole position to qualify as Group H winners.

They only need a draw against Morocco to top the pool.

Germany, stunned by Colombia and 18-year-old attacker Linda Caicedo in their previous match, are through with a win over a South Korea side who are more or less already out.

Caicedo underwent X-rays after health scares at the tournament but is "100 per cent" fit for the Morocco game, coach Nelson Abadia said.

The teenage Real Madrid attacker, who was diagnosed with ovarian cancer at 15 but made a full recovery, has lit up the World Cup with goals in wins against South Korea and Germany.

In the upset over two-time champions Germany Caicedo scored one of the goals of the tournament, days after going down in training clutching her chest.

She also appeared to suffer breathing difficulties in that 2-1 win – which took Colombia to the brink of the last 16 – but carried on playing.

Abadia said X-rays on Caicedo had not detected any issues.

"She went through a check-up... to be sure that she is at 100 per cent. You can be assured that she is at 100 per cent," Abadia told reporters in Perth.