Having a large body, long tentacles, sharp beak and sucker ring teeth to battle against a sperm whale in deep water makes the giant squid, Architeuthis dux, capture imaginations and constantly fire debate and interest. The hunting strategy of the giant squid in the twilight realm, particularly how to manipulate the soft and long tentacles (e.g.>5m length of a subadult), to catch prey, remains largely unknown. Here we present the first in situ behavioural observation of the tentacular strike of the giant squid which attempted to capture the artificial bioluminescent lure in its natural habitat (800 m depth), off Australian waters. Firstly, this footage confirmed that two long tentacles can be firmly held together by extensive paired locking apparatus (smooth-ringed suckers and knobs), along the tentacular stalks. The elastic locked tentacles bearing nimble tentacular clubs allow a ballistic strike onto a small light lure in distance. Also, the remarkably rapid changes of arrangement of tentacular clubs from the noose shape to the claw-like structure to grasp objects indicate that the giant squid likely relies on good vision (enormous eyes), chemotactile (suckers), or both for prey hunting.