Four teams remain in contention for the HSBC USA Sevens Cup title after a second enthralling day of action at the Sam Boyd Stadium in Las Vegas.
After a second pulsating day in front of 35,716 fans, USA beat Kenya to set up a semi-final with defending champions Fiji on day three, while South Africa await Australia after beating New Zealand for the first time since the 2014 Port Elizabeth Sevens.
In the first quarter-final Mike Friday's hosts beat his former side Kenya 26-14 to delight of the home crowd and booked their place in the last four of the fifth round on the HSBC World Rugby Sevens Series thanks to tries from Danny Barrett, Perry Baker, Martin Iosefo and Zack Test.
Kenya had earlier beaten New Zealand 22-0, their first win over the All Blacks Sevens side since the 2013 Wellington Sevens, to top Pool A before coming up short against the USA despite Collins Injera scoring his fourth try of the weekend and 218th overall.
Ben Ryan's Fiji bounced back from their opening pool match defeat to Samoa to top Pool C thanks to a narrow 15-12 win over Argentina before beating Japan 36-7 in the quarter-finals. Two tries from Jasa Veremalua and one each for captain Osea Kolinisau, Jerry Tuwai, Pio Tuwai, Savenaca Rawaca and Amenoni Nasilasila proved the difference and setting up a semi-final with the hosts.
RE:LIVE! Jerry Tuwai TONIGHT! Fiji impress against Japan to reach last four in Vegashttps://t.co/awugIWeacG— World Rugby Sevens (@WorldRugby7s) March 6, 2016
Japan had beaten Scotland 26-19, adding to their 19-19 draw with England on day one, to secure their place in a Cup competition for the first time since the 2015 Tokyo Sevens and only third time in history, but could not stop the reigning series champions.
The Blitzboks will meet Australia in the second semi-final after Seabelo Senatla scored his eighth and ninth tries of the tournament to help his side beat the Wellington and Sydney champions New Zealand 14-7. It was Neil Powell's first win over Sir Gordon Tietjens since the 2014 Port Elizabeth Sevens, ending a run of five successive defeats.
In the fourth quarter-final tries from Ed Jenkins, Allan Fa'alava'au and two from Sam Myers gave the HSBC Sydney Sevens runners-up to a 26-12 win over Los Pumas.
England's disappointing tournament continued, suffering a 36-7 defeat to Australia, a match in which Quade Cooper scored his first try in rugby sevens, to finish bottom of a pool for the first time since the 2013 Hong Kong Sevens.