The incident happened at a home on Myrtle Avenue in West Haven around 1:30 a.m.
Authorities say a resident of the home subdued one suspect and held him down until police arrived, and a woman in the house stabbed the other man multiple times in his head and neck.
The injured suspect fled the scene and remains on the loose.
The other suspect, who was taken into custody, was identified as Roderick Lewis.
Officers are searching for the other suspect by using a police dog and checking area hospitals.
(Information from the Associated Press was used in this report)