Tony Drago and Neil Robertson were surprise losers in the last 16 of the World Games in Bottrop, Germany on Thursday.

Malta's world No 36 Drago lost 3-0 to Malaysia's Keith E. Boon. Drago struggled to get used to the table conditions and Boon cruised to success with best breaks of 31 and 35.

Robertson, the world No 28, suffered a 3-1 reverse against home favourite Lasse Munstermann.

The German player now faces a tough quarter-final tie against China Open champion Ding Junhui.