Four remain unbeaten in Tokyo
Samoa, Fiji and New Zealand won all three of their matches on Day One at the Tokyo leg of the IRB Sevens World Series.
On a day where conditions were the polar opposite to the humid Hong Kong last weekend, Samoa beat Australia in a reverse of last year's Cup Final result to top Pool D and set up a Cup quarterfinal with South Africa on Day Two.
Last weekend's champions Fiji will meet the defending champions Australia, while Scotland also went unbeaten on Day One after drawing 12-12 with the United States to add to two earlier victories and will meet France.
Both Scotland and United States progress to the Cup quarterfinals from Pool C, with both sides looking for important Series points to help their positions of 12th and 14th respectively, and the United States will play Series leaders New Zealand in other quarterfinal.
Earlier, hosts Japan caused the biggest shock of the day as they beat Canada 14-10.
United States also recorded a 24-22 against last week's finalists Wales who enter the Bowl alongside England. Ben Ryan's side will be competing in a sixth Bowl of the season after recording just one victory on Day One.
Cup quarterfinals:
Fiji v Australia
New Zealand v United States
Samoa v South Africa
Scotland v France
Bowl quarterfinals:
Spain v Argentina
Canada v Kenya
England v Portugal
Wales v Japan
We look at all the Day One drama!
Pool A:
Last week's champions Fiji got off to a flying start against United States Sevens champions South Africa, winning 29-12, before they fought off a spirited Spain 17-5. In their third match they proved too strong for Portugal, winning 22-7 and will face defending champions Australia in the Cup quarters.
Spain beat Portugal in the all-Iberian affair earlier on Day One, as points at the bottom of the standings became just as crucial, before South Africa also beat Portugal, 12-0, with Cornal Hendricks scoring his 29th try of the season.
Paul Treu's side then scored six tries, including 18 points from Branco du Preez, in a 42-5 defeat of Spain to progress to the Cup quarterfinals.
Results:
Fiji 34-7 Portugal
South Africa 42-7 Spain
Portugal 0-12 South Africa
Fiji 17-5 Spain
Portugal 14-17 Spain
Fiji 29-12 South Africa
Pool B:
United States caused the first upset of Day One as they beat last week's finalists Wales 24-22 in a pulsating encounter with Matt Hawkins scoring one of the tries of the day. Colin Gregor impressed in Scotland's victory against Kenya, scoring the first and then turning provider with a wonderful kick for Darren Gillespie.
Kenya responded well in their second match, defeating United States 21-10 with in an enthralling match with Zach Test scoring perhaps the try of the day. The United States ended their Day One with a 12-12 draw with Scotland who ended the day unbeaten to progress to the Cup as Pool B winners and the United States joining them in the Cup quarters.
Wales saved their blushes on Day One at the Tokyo Sevens, recording their first victory at the end of Day One against Kenya 33-15 having lost to Scotland 12-10 earlier on Day One.
Results:
Wales 33-15 Kenya
United States 12-12 Scotland
Kenya 21-10 United States
Wales 10-12 Scotland
Kenya 0-12 Scotland
Wales 22-24 United States
Pool C:
New Zealand got off to a winning start as they look to extend their lead at the top of the Series, beating France 26-7 thanks to Tim Mikkelson scoring his 101st try and a 41-5 defeat of the hosts Japan thanks to a hat-trick from Sherwin Stowers.
Jamie Henry scored on his Japan Sevens debut as they beat Canada 14-10 to the delight of the home crowd, before Canada recovered from that shock to narrowly beat France 22-19.
In the penultimate match of Day One France proved too strong for Japan as the hosts lost 24-7 before the Series leaders defeated Canada 22-12 to secure their place as Pool C winners and relegate Canada to the Bowl.
Results:
New Zealand 24-12 Canada
France 24-7 Japan
Canada 22-19 France
New Zealand 41-5 Japan
Canada 10-14 Japan
New Zealand 26-7 France Pool C
Pool D:
Last year's finalists both progressed to the Cup quarters after they won their opening two matches. Australia made it two wins from two as they look to defend their title in Tokyo, beating Argentina 31-0, before Samoa impressed against England winning 31-21 scoring two outstanding late tries through Tulolo Tulolo and Levi Asifa'amatala.
In the Pool D decider Samoa beat Australia 26-14 in a repeat of last year's Cup final, a reverse of the result, before England beat Argentina 31-7 for their first win of the day. England will compete in their sixth Bowl of the season.
In the day's opening two matches, defending champions Australia beat England 26-19 in a pulsating encounter for the fans. Last year's runners-up Samoa left it late in their match, Reupena Levasa scoring with the last play to beat Argentina 17-14.
Results:
Australia 14-26 Samoa
England 31-7 Argentina
Samoa 31-21 England
Australia 31-0 Argentina
Samoa 17-14 Argentina
Australia 26-19 England