Las Vegas - Two-time defending champions South Africa have rallied for a 21-14 win over England on Saturday to reach the Cup semi-finals of the Las Vegas Sevens.
Tries from Branco du Preez, Seabelo Senatla and Kwagga Smith lifted the Blitzboks, who next face Fiji who clinched a 31-12 win over France.
The United States booked their first semi-final berth since the 2010 Adelaide Sevens with a 20-0 win over regional rivals Canada. But the hosts will face a stiff challenge in New Zealand, who thumped Australia 28-7 in their quarter-final.
Australia had joined Fiji as the only team to emerge unbeaten from pool play, but a hat-trick from Joe Webber proved too much in the loss to New Zealand.
The United States got off to a quick start against Canada, with Danny Barrett crashing over in the corner shortly followed by tries to Folau Niua and crowd favourite Zack Test for a 15-0 lead at half time.
USA speedster Carlin Isles stretched the lead to 20-0 enough to get the hosts home in front of 34,593 fans.
Four tries to Savenaca Rawaca set Fiji up for a 24-0 lead at half-time over France. Jean Marcellin Buttin put France on the board shortly after the break before Sitiveni Waqa added to Fiji's lead before a late consolation to Bryan Dimeck.
The four losing Cup quarter-finalists will contest the Plate semi-finals, chasing valuable series points as qualifying for the 2016 Rio Olympics continues.
Meanwhile, Samoa will meet Kenya and Scotland face Argentina in the Bowl semi-finals.
Samoa downed Brazil 26-7, Kenya beat Portugal 17-7, Scotland edged Wales 19-14 and Argentina defeated Japan 15-12 in the quarters.
Pool play that began on Friday wrapped up on Saturday with the United States, already assured of a quarter-final spot, playing to an enthralling 19-19 draw with South Africa to finish second in their pool on points difference.
Canada, who shocked England on Friday, beat Argentina 24-7 to reach their first Cup quarter-final of the season.
England, meanwhile, secured their Cup quarter-final berth with a 21-14 win over Kenya, after leading 14-0 at halftime.
Tries for Richard de Carpentier and Tom Mitchell provided the early breathing space before Oscar Ayodi hit back for Kenya early in the second half.
Charlie Hayter responded for England extending the lead back out to 14 but Kenya kept England playing as Tony Opondo scored late.
Results from Saturday's second day of the USA Sevens:
Fiji 31 France 12
South Africa 21 England 14
Australia 7 New Zealand 28
Canada 0 USA 20
Samoa 26 Brazil 7
Portugal 7 Kenya 17
Scotland 19 Wales 14
Argentina 15 Japan 12
Wales 19 Samoa 26
New Zealand 12 Fiji 14
Argentina 7 Canada 24
England 21 Kenya 14
Portugal 21 Japan 19
South Africa 19 USA 19
France 26 Brazil 7
Scotland 14 Australia 40