Two defeats in Pool B against Canada in the opener and Blitzbokke in their must win last match after success against Wales provided hope saw Kenya relegated to the Bowl quarters where they beat Spain 24-0 to qualify for the semis.
However, that is scant consolation for Treu after his side fell to his former employers for the third time in a row following defeats in Dubai and George with Werner Kok, Stephan Dippenaar and Seabelo Senatla scoring the tries, two which were converted, to send Kenya crashing out of the Main Cup.
Stand-in skipper, Collins Injera, scored his 169th try for Kenya to level matters after Kok went over at the stroke of half time with Biko Adema’s boot bringing the sides level.
South Africa, winners of the Nelson Mandela Bay 7s in George, returned after the breather and after Billy Odhiambo was sin-binned to leave Treu’s charges a man short, Dippenaar grounded the ball with Cecil Afrika missing the convertion.
Barely three minutes later, Senatla put further distance between his team and Seabelo Senatla duly converted to seal the result.
With Canada beating Wales 21-19 in a close encounter, South Africa sealed top spot as Kenya slipped to third and Bowl quarters against Spain.
Injera got Treu’s charges off the mark with 4:16 gone before Odhiambo got into the act to give Kenya a 10-0 lead at the breather.
Horace Otieno and debutant Tony Owuor added two converted tries to round up the win as Kenya failed to make the Main Cup quarters for the first time this season as they set up a meeting with Scotland in the Bowl semis.
As Kenya faltered, Pool B rivals Canada performed heroics to reach only their second-ever Cup semi-final in IRB Sevens rugby, joining defending USA Sevens champions South Africa, New Zealand and Samoa in the final four.
The South Africans, the most recent winners on the HSBC Sevens World Series, have conceded just seven points in their four matches so far at the Sam Boyd Stadium and beat Argentina 36-0 in their quarter-final with tries by Cecil Afrika, Branco du Preez, Seabelo Senatla, Chris Dry (2) and Werner Kok.
They next face Samoa in an enthralling match-up between the only two sides to have won a Cup in Las Vegas.
The 2010 and 2012 champions, Samoa, came from 10-0 behind to beat Australia 12-10 with tries from Sani Niue and Lio Lolo.
In another enthralling quarter-final Canada came from 14-0 behind to reach their first Cup semi final since the Tokyo Sevens back in 2000, defeating France 17-14 with Connor Braid scoring two tries before Nanyak Dala snatched the win.
The Cannucks will face Series leaders New Zealand after the All Blacks Sevens proved too strong for England in the last of the quarter-finals, winning 24-7 spear-headed by a hat-trick from Waisake Naholo.
Gordon Tietjens’ side will be without George Tilsley for one more match, however, and Sam Dickson for eight more matches after both players received disciplinary sanctions following their match with Fiji.