US Bankruptcy Judge Steven Rhodes settled into his chair shortly after 14:00 GMT. The city wants him to put a stop to lawsuits in other courts, especially after an Ingham County judge said state officials ignored the constitution and acted illegally in approving the bankruptcy last week.
The state appeals court temporarily stopped three lawsuits challenging the bankruptcy process on Tuesday.
As lawyers for some of the thousands of creditors arrived Wednesday, they passed protesters holding a banner saying: "Cancel Detroit's debt. The banks owe us."
The case is expected to last at least a year.