Her breakthrough into leading roles was provided when prima donna Marie Goetze argued with the director of the Hamburg opera. He asked Ernestine to sing the title role of "Carmen", without rehearsal, which she did to great acclaim. Goetze, in a fit of pique, cancelled out of the role of Fidès in "Le prophète", to be performed the following night, and was again replaced by Ernestine. Schumann-Heink replaced Goetze as Ortrud in "Lohengrin" the following evening, one more time without rehearsal, and was offered a ten-year contract.