(1) Blood in the Water match https://en.wikipedia.org/wiki/Blood_in_the_Water_match
(2) (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). (このあと、例文が3つもある) https://en.wiktionary.org/wiki/blood_in_the_water
