Noun
blood in the water (uncountable)
(idiomatic) In a competitive situation, the exhibition of apparent weakness or vulnerability by one party, especially when this leads to a feeling of vulnerability or greater pressure to perform on the part of the weak party, and/or enhanced expectation of victory by the other(s).
You don't have to be a political genius to sniff the smell of blood in the water. Rich Galen
The Blood in the Water match has since been the subject of several documentaries and films. Source: Internet