The United States was the only team to upset the apple cart — though Canada and Japan both came close to pulling off shock wins — as Round 6 of the HSBC Sevens World Series got under way Saturday at the Prince Chichibu Memorial Rugby Ground.

On the same day its 15s team was taking on Uruguay in a Rugby World Cup qualifier, the United States came from behind to beat Samoa 24-17, drew 19-19 with Fiji and then lost 22-12 to France. But with Fiji beating Samoa 33-7 in the final game of Pool C, the Americans advanced to the main Cup competition for the first time this season.

American heroics aside, it was business as usual though as New Zealand, South Africa, Fiji and the other big guns advanced to the quarterfinals, in front of a very multinational crowd.

New Zealand, which leads the series by two points, survived a scare against Canada, winning 22-17 with a try in the final seconds to win Pool A. The Canadians took some consolation though, as they edged Wales for second place on try differential.

South Africa (second in the standings and Tokyo champions last year) won Pool B from Kenya, Argentina and Japan, while England topped Pool D from Australia (which won here two years ago) after coming from behind to beat its rival 24-21 in a thriller.

Japan, which as host is playing in its only tournament of the 2013-14 series, finished the day with one draw and two defeats to its name and will start Sunday in the Bowl. But it did score arguably the try of the day through Jamie Henry in its loss to South Africa, and pushed Kenya all the way after opening the day with a draw against Argentina, which finished third on account of scoring more points than Japan.

If it can tighten up its defense and learn not to throw and kick away possession, Japan may not only give the crowd something to really cheer about Sunday but also put together a good run ahead of next week's crucial qualifying tournament in Hong Kong that sees it and 11 other teams fight it out for one spot among the 15 core teams on next year's circuit.

Japan's 14-14 draw with Argentina was no mean feat, given the South Americans had progressed to the quarterfinals at each of the last four tournaments.

But it was a case of a lost opportunity as the Brave Blossoms Sevens had their chances to win only for some poor handling and defense to let them down.

Two tries by Lomano Lemeki had seen Japan take a 14-0 lead, but three missed tackles on Joaquin Cachi Paz allowed Argentina to pull back to 14-7 at the break.

The second half was an error-strewn affair with Argentina making the most of it to score through Gonzalo Gutierrez Taboda and then hold on as Japan once again spilled the ball at the death.

"We made too many mistakes, but we'll fix them and play well in the next game," said Lemeki.

Unfortunately, that was not to be as Japan's lack of big-match experience and bulk cost it big-time against South Africa, as it went down 33-5.

Despite dominating territory early on, Japan was unable to turn pressure into points. And as the players tired and fell off their tackles, the BlitzBokke took full advantage running in five tries, though not before Henry raised the roof by chasing a kick ahead and finishing off with a superb dive into the corner.

"We have to get in the right position to make our tackles and cut down on the mistakes," said Yoshikazu Fujita.

Japan finished off the day by pushing Kenya hard, but once again let itself down by kicking the ball away at crucial times.

The Kenyans led 12-0 at the half, but a much-improved second half from the hosts saw Fujita cross the whitewash, with Katsuyuki Sakai adding the extras. A place in the quarterfinals beckoned but Japan was unable to break the Kenyan defensive line, leaving it to face Samoa when the competition resumes Sunday.