Godoy Cruz coach Jorge da Silva resigned on Wednesday despite steering his team into the 2012 Copa Libertadores and receiving backing from players, directors and fans.
"There were things I didn't like that happened at the club during the last matches that we had lost," Da Silva told reporters about the criticism at the club during a recent lean spell.
"There were people who cast doubt over my work so I decided to resign," the 49-year-old Uruguayan added.
Godoy Cruz, from the western Andean province of Mendoza, ended a run of four matches without a victory and eight with only one win when they beat Atletico Rafaela 2-0 on Monday to secure their place in South Americas elite club competition.
Da Silva, a former Atletico Madrid, River Plate and Uruguay striker, was the eighth coach in the Apertura, first of two championships in the Argentine season, to resign or be sacked.
The Clausura championship and the Copa Libertadores both kick off in February after the summer recess.