A SECURITY guard who stabbed his colleague to death with a beef knife in revenge for previous bullying was yesterday cleared of murder. Wang To-sang, 54, was convicted of manslaughter after a High Court jury decided he had attacked Fok Shui-wah under provocation. Fok, 49, nicknamed 'Short-legged Tiger', collapsed in a pool of blood in front of horrified colleagues. The two men came to blows after tempers boiled over as they changed for work at Cornwall House, Taikoo Place, Quarry Bay, on May 9 last year. Prosecutor Robert Forrest said the fight began with pushing and shoving but degenerated into an ugly brawl. 'Fok got hold of two light metal rods used as rails for hanging clothes. After that, the defendant armed himself with a beef knife. 'Fok retreated out of the changing room still carrying the two aluminium rails. The defendant followed him outside.' Mr Forrest said no one witnessed the attack but, moments later, Fok staggered into the changing room clutching his stomach and with blood all over his hands. The jury was shown the 30-centimetre beef knife and the clothes rails, still covered in blood. A postmortem examination revealed that Fok died from a knife wound which had punctured his lung and liver. Wang told police he stabbed Fok because he was 'blinded by rage' but had not meant to kill him. Mr Justice Leong adjourned mitigation and sentencing until next Friday.