Reigning Singapore Sevens champions Kenya Sevens gave themselves a chance to defend their crown after winning two of their group matches to finish second in their Pool.
Shujaa started their title defence against Argentina who they swatted aside 22-7. They were then outclassed 29-7 by group winners Australia, making their clash against Samoa a must win.
Samoa were the first to register points on the board with a converted try. Captain Andrew Amonde replied and with Sammy Oliech converting, it was 7-7 at the breather.
Samoa lost two men to the sin bin and Kenya capitalized with Billy Odhiambo pulling them ahead before Nelson Oyoo put the game to bed with a debatable try and a 17-7 victory for Innocent Simiyu's side.
With Australia beating Argentina 19-7, Shujaa qualified for the quarters for only the second time this season.
Their opponents in the anti-penultimate round will include Canada, Fiji, New Zealand, USA and Australia.
Kenya thumped Fiji 30-7 in the Singapore 7s Main Cup final last year to win their maiden series leg in history.
They have however not gotten any close to hitting those heights this season and have been regular participants in the Challenge Trophy competition, emerging champions twice.
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