Just before 8 p.m. (1200 GMT) on Saturday, Kuwait's Ali Zankawi lined up for one of his throws in the men's hammer final at the eastern Chinese city's packed Olympic stadium.
But instead of soaring straight onto the outfield, the hammer flew out sideways and low to the right, smashing into the leg of the sitting technical official.
Looking horrified, Zankawi sprinted over as blood began spurting from the official's right leg.
The official, Huang Qinhua, 62, grimaced and swayed dizzily as Zankawi rushed to check on him, blood shooting out of the wound.
The netting in athletics is designed to hang relatively loosely to prevent hammer balls and discuses from bouncing back at the athletes after misthrows.
Persons:
Kuwait's Ali Zankawi, Dylan Martinez, Zankawi, Huang Qinhua, grimaced, dizzily, Huang, Xu Deqing, China's Wang Qi, Martin Quin Pollard, William Mallard
Organizations:
Olympic Sports Centre, Rights, Asian, misthrows, Weibo, Thomson
Locations:
Hangzhou, China, Rights HANGZHOU